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Difficulty: Very hardSummary: Distinguishing Essential Ideas from Irrelevancies

Read the passage below carefully and answer the question that follows:

Across the coastal belt of the Niger Delta, mangroves serve as natural biophysical barriers, dissipating wave energy and stabilizing fragile shorelines against systemic erosion. Over the past four decades, extensive industrial logging, oil exploration spills, and unchecked urban expansion have severely fragmented these estuarine ecosystems. While artificial sea defenses—such as concrete seawalls and granite revetments—have been widely deployed by local municipal planners to curb immediate storm surges in coastal settlements like Bonny and Forcados, marine ecologists emphasize that these engineering structures are financially unsustainable and ecologically disruptive over the long term. Engineered barriers frequently exacerbate erosion in adjacent unfortified coastlines by altering natural sediment transport dynamics. Conversely, regenerating native Rhizophora mangrove species restores natural sedimentation traps, revives local fisheries, and sequesters vast amounts of blue carbon at a fraction of the maintenance cost. Thus, while engineered sea defense projects remain a popular quick-fix intervention for municipal authorities facing urgent shoreline retreat, comprehensive ecological restoration of native mangrove forests constitutes the essential, sustainable foundation for long-term coastal resilience in the region.

Which of the following statements best expresses the central argument of the passage, distinguishing the core message from supporting details?

  1. Long-term coastal defense in the Niger Delta depends primarily on restoring native mangrove ecosystems rather than relying on artificial engineering solutions.Answer
  2. B
    Concrete seawalls and granite revetments in settlements like Bonny provide effective immediate protection against severe storm surges.
  3. C
    Municipal authorities in the Niger Delta plan to completely prohibit all industrial logging and oil exploration to eliminate shoreline retreat.
  4. D
    Engineered sea defenses trap natural sediment efficiently, making them more cost-effective than native Rhizophora mangrove regeneration.

Answer

Long-term coastal defense in the Niger Delta depends primarily on restoring native mangrove ecosystems rather than relying on artificial engineering solutions.
The correct answer accurately synthesizes the passage's main message: ecological restoration of native mangroves is the vital, long-term solution for coastal defense in the Niger Delta, superior to temporary artificial engineering structures. The passage uses references to seawalls, specific towns, and sediment dynamics as secondary supporting evidence to reinforce this primary argument.

Step-by-Step Solution

1
Analyze the passage structure to separate the core argument from illustrative supporting information.
Identified that mentions of specific structures (seawalls/revetments), locations (Bonny/Forcados), and specific ecosystem services (fisheries, carbon sequestration) serve as supporting evidence and examples.
Supporting details elaborate on why or where a phenomenon occurs but do not constitute the primary message.
2
Identify the author's central thesis and concluding claim.
The final sentence explicitly frames ecological mangrove restoration as the essential, sustainable foundation for long-term coastal resilience, contrasting it with artificial quick fixes.
Summary items require identifying the overarching synthesis statement that encapsulates the entire text.
3
Evaluate the choices against the central thesis to select the option that expresses the core idea without focusing on secondary details.
The option emphasizing mangrove restoration as the primary foundation for coastal defense over artificial engineering is the only choice that represents the complete core argument.
The correct summary must cover the main thesis and avoid minor supporting points or false inferences.

Key Concept

Summary: Distinguishing Essential Ideas from Irrelevancies
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Summary: Distinguishing Essential Ideas from Irrelevancies

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