Critical Reasoning

Historical records from 19th-century oceanic expeditions indicate a 40 percent decline in sperm whale sightings along the North Atlantic migration route between 1840 and 1860. Marine historians attribute this decline exclusively to overharvesting by commercial whaling fleets operating in the region. However, archival logbooks from active whaling vessels during those decades reveal that the average catch yield per vessel remained entirely constant throughout the twenty-year period. Which of the following statements represent necessary assumptions upon which the marine historians' argument depends? Select all that apply.

To mitigate drought-related crop failures, a regional agricultural council launched a subsidy encouraging farmers to adopt no-till seeding, a technique that leaves crop residue intact to retain soil moisture. The council predicts that widespread adoption of no-till seeding will significantly increase overall regional grain yields during severe drought years. Opponents point out that no-till seeding requires specialized planting equipment that consumes twice as much fuel per acre as traditional tillage implements.

Which of the following statements, if true, strengthen the agricultural council's prediction regarding overall grain yields? Select all that apply.

A municipal transportation authority installed high-definition security cameras across all urban railway platforms last year to deter vandalism. Over the subsequent twelve months, reported incidents of platform vandalism decreased by thirty percent. The authority concluded that the installation of the security cameras was the primary factor in reducing platform vandalism. However, during the exact same twelve-month period, the city doubled the number of uniformed police officers patrolling those platforms.

The reasoning in the transportation authority's argument is most vulnerable to criticism on the grounds that it

To reduce operational overhead and improve employee retention, a financial services firm mandated a hybrid work schedule allowing employees to work remotely three days a week. Following the policy's implementation, total energy consumption at the firm's headquarters decreased by 30 percent, and employee turnover dropped by 15 percent. Management concluded that the hybrid policy was directly responsible for the reduction in facility operating costs and the increase in worker retention. Which of the following statements, if true, most seriously undermines the management's conclusion?

A botanical survey of an alpine valley established that the blue alpine gentian blooms exclusively at elevations above $2,500$ meters. Researchers also determined that the mountain bumblebee, which serves as the sole pollinator for the blue alpine gentian, cannot survive in habitats where the average summer temperature exceeds $15^\circ\text{C}$. Over the past decade, average summer temperatures across all areas of the valley situated between $2,200$ meters and $2,600$ meters in elevation have consistently exceeded $15^\circ\text{C}$.

If the statements above are true, which of the following must also be true on the basis of them?

Recent genomic sequencing of ancient emmer wheat grains recovered across Near Eastern archaeological sites reveals a striking pattern: despite centuries of deliberate cultivation, genetic diversity remained virtually constant until a sudden, severe bottleneck occurred around 7,000 BCE. Archaeological historians traditionally attributed this shift to catastrophic climate aridification that forced farmers to rely on a few resilient cultivars. However, isotopic analysis of contemporary livestock teeth indicates stable precipitation levels and diverse forage during this exact period. Instead, the sudden homogenization coincides precisely with the widespread adoption of centralized, state-managed seed storage facilities. Therefore, early administrative centralization, rather than environmental stress, was the decisive driver behind the reduction in crop genetic variation.

Based on the passage above, which of the following statements express a main conclusion or primary claim advanced by the argument? Select all that apply.

Archaeologists examining a 3,000-year-old Mediterranean shipwreck discovered several deposits of birch bark pitch, a compound historically used as a waterproof sealant. Because the pitch residues were found exclusively along the inner seams of the vessel's lower cargo hold rather than on the ceramic storage containers themselves, researchers concluded that the pitch was applied directly to seal the ship's wooden timbers during construction, rather than originating from leaked commercial cargo.

Which of the following, if true, most strengthens the researchers' argument?

To reduce light-induced degradation of delicate seventeenth-century oil paintings, curators at the Vane Gallery replaced all traditional halogen spotlights with light-emitting diode (LED) fixtures that emit zero ultraviolet radiation. Because ultraviolet rays were previously identified as a chief contributor to varnish oxidation, the curators concluded that overall pigment and varnish breakdown in the gallery's collection will decrease by at least 40 percent over the coming decade. Which of the following statements, if true, most seriously weakens the curators' argument?

In 2021, the government of Region Y introduced a high-precision satellite irrigation system free of charge to commercial rice farmers, aiming to reduce total groundwater consumption in the agricultural sector. Over the subsequent four years, water metering data confirmed that every participating farm reduced its water usage per metric ton of harvested rice by an average of thirty percent, and no new rice farms were established in the region. Nevertheless, overall agricultural groundwater depletion in Region Y accelerated substantially over the same four-year period.

Which of the following, if true, best reconciles the apparent discrepancy described above?

A major commercial airline implemented a fleet-wide routing and weight-optimization program that successfully reduced average fuel consumption per passenger-mile by 12 percent across its international operations over a two-year period. However, financial and operational audits revealed that during the exact same two-year period, the airline's total fuel expenditure for international flights increased by 18 percent, even though global jet fuel prices remained completely unchanged throughout this timeframe.

Which of the following statements, if true, help to resolve the apparent discrepancy described above? Select all that apply.

In 2024, a national banking regulator required all financial institutions within its jurisdiction to adopt a new high-security biometric authentication system for online transactions, replacing password-based access to curb digital fraud. Eighteen months after full implementation, official data revealed that over 90 percent of retail banking customers routinely used the biometric system. Paradoxically, over the same 18-month period, the total monetary losses incurred by commercial banks due to online banking fraud rose by 28 percent nationwide.

Which of the following statements, if true, help(s) to resolve the apparent discrepancy described above? Select all that apply.

Economists traditionally argued that implementing tariff protection on infant industries inevitably undermines long-term domestic competitiveness by shielding firms from global market pressures. However, a comprehensive analysis of East Asian industrialization reveals that several key sectors achieved international dominance precisely during periods of heavy protection. These historical outcomes suggest that targeted state protection can foster competitive advantages when paired with strict export performance standards. Granted, protectionism often induces economic inefficiency when unconditioned; nonetheless, since conditional subsidies incentivized rapid technological adoption in these case studies, the conventional view regarding the uniform detriment of tariff protection requires substantial revision.

In the argument given, the two boldfaced portions play which of the following roles?

To combat regional power grid instability, energy directors plan to construct geothermal plants along an active fault line, where subterranean heat is greatest. Skeptics claim that drilling deep geothermal wells in seismically active areas risks triggering earthquakes that damage local infrastructure. However, the lead engineers contend that operating these geothermal facilities will net a decrease in major seismic hazards. They reason that extracting subterranean thermal energy cools surrounding rock formations, inducing thermal contraction that gradually dissipates accumulated tectonic tension via harmless micro-tremors rather than catastrophic faults. Which of the following, if true, provides the strongest support for the lead engineers' contention?

In 2022, a major timber enterprise operating across Region Z replaced its entire fleet of diesel-powered logging machinery with advanced autonomous electric harvesters designed to eliminate direct tailpipe emissions and optimize cutting paths. Following the complete transition, the enterprise reported a 40 percent reduction in carbon emissions per ton of timber harvested. However, during the two years following the equipment replacement, the enterprise's total annual operational carbon emissions across Region Z actually increased by 15 percent.

Which of the following, if true, most helps to resolve the apparent discrepancy described above?

Archaeological analysis of the 4th-century BCE Mediterranean shipwreck *Phaedra* recovered hundreds of ceramic amphorae containing olive oil alongside silver coins minted exclusively in Athens between 340 BCE and 320 BCE. Spectroscopic testing established that all olive oil in the cargo was produced in Southern Italy. Historical documents confirm that during this twenty-year period, Athens levied heavy duties on foreign agricultural products sold within Attic territories, but exempted items transshipped through Athenian ports for export elsewhere. Additionally, Athenian silver coins from this specific era undergo total chemical decomposition when continuously submerged in marine saltwater for more than two centuries.

Based on the passage above, which of the following statements must be valid inferences? Select all that apply.

While marine biologists traditionally attributed coral bleaching exclusively to acute thermal stress, recent longitudinal studies of Pacific barrier reefs suggest a more complex dynamic. Resilient coral colonies facing elevated sea temperatures do not merely retain their existing algal endosymbionts; rather, they actively shuffle their internal clade composition, favoring stress-tolerant Symbiodiniaceae strains over high-growth variants. However, this physiological adaptation comes at a measurable metabolic cost, as stress-tolerant symbionts transfer significantly fewer photosynthetically derived carbohydrates to the host organism, thereby constraining long-term skeletal calcification. Consequently, thermal adaptation strategies that focus solely on symbiont diversity overestimate long-term reef viability if calcification deficits remain unaddressed. Therefore, effective marine conservation interventions must prioritize mitigating local water pollution that compounds calcification stress alongside global climate initiatives.

Which of the following statements represent main conclusions or primary claims advocated by the author of the passage? Select all that apply.

Although twentieth-century archivists long maintained that the adoption of paper-making technology in medieval Europe immediately displaced parchment due to paper's lower production costs, historical trade manifests from Mediterranean ports reveal a far more nuanced transition. Parchment production actually peaked several decades after paper mills were established in northern Italy, as administrative scribes continued to demand parchment for legal instruments requiring longevity. Consequently, the rapid proliferation of paper mills was driven not by the obsolescence of parchment in official record-keeping, but rather by the surge in merchant correspondence and informal ledger accounting.

Which of the following best expresses the main conclusion of the argument?

Under the 2024 Agro-Export Reform Act, any regional grain cooperative seeking federal tariff exemptions must obtain a Grade-A sustainability certification. To qualify for Grade-A status, a cooperative must either reduce its synthetic nitrogen runoff by at least $35\%$ relative to 2020 levels or transition at least $50\%$ of its cultivated acreage to organic soil management. Furthermore, no cooperative that receives municipal water subsidies is eligible for federal tariff exemptions, regardless of its sustainability certification level. Last year, the Sun Valley Agricultural Cooperative received a federal tariff exemption under the Act.

Consider each of the choices separately and select all that apply. Which of the following statements must be true based on the information above?

A municipal water authority plans to filter industrial heavy-metal runoff by deploying permeable bio-char barriers produced from Melaleuca wood, an invasive tree species currently being cleared from local wetlands. Environmental engineers argue that this initiative will simultaneously reduce heavy-metal contamination in the municipal water supply and lower overall wetland restoration costs. They base this claim on data showing that Melaleuca bio-char binds heavy metals with high efficiency in laboratory settings, and that harvesting the wood for bio-char production will offset the expenses of clearing the invasive trees.

Which of the following statements represent necessary assumptions upon which the engineers' argument depends? Select all that apply.

Paleontologists long hypothesized that the unusually dense, vascularized bone structure observed in the fossilized limb bones of Spinosaurus served primarily to provide ballast for underwater foraging. However, a recent biomechanical study demonstrated that several terrestrial archosaurs exhibited comparable bone density without engaging in aquatic habits. Therefore, this structural feature does not, by itself, demonstrate an exclusively aquatic lifestyle, though it remains consistent with semi-aquatic behavior when evaluated alongside cranial adaptations.

Which of the following statements accurately describe the rhetorical functions of the boldfaced portions in the argument? Select all that apply.