Read the passage below carefully and answer the question that follows.
Bio-mineralization in cold-water corals present along continental margins plays a pivotal role in constructing deep-ocean structural habitats that sustain marine biodiversity. Unlike shallow-water reef systems that rely primarily on symbiotic photosynthetic algae for energy and skeletal calcification, deep-sea corals inhabit cold, aphotic environments where calcification is driven entirely by heterotrophic feeding on organic detritus and zooplankton. Despite the energetic costs of secreting aragonite skeletons in low-carbonate-saturation waters, these slow-growing organisms form vast, intricate three-dimensional reefs over millennia. Recent oceanographic monitoring reveals that shifting ocean currents and thermal stratification reduce the downwelling of organic matter from surface waters. This nutritional deficit severely impairs the corals' metabolic capacity to maintain skeletal growth and repair structural damage caused by naturally corrosive acidic waters. Consequently, the long-term structural integrity of these deep-water ecosystems is primarily governed by the availability of surface-derived organic energy rather than ambient water temperature alone.
Which of the following statements best expresses the primary argument of the passage?
- The structural durability of cold-water coral ecosystems relies fundamentally on surface-derived nutrient supplies to sustain bio-mineralization against corrosive ocean conditions.Answer
- BCold-water corals construct deep-ocean habitats by feeding heterotrophically on organic detritus and zooplankton rather than utilizing photosynthetic algae.
- COcean thermal stratification and shifting currents will rapidly cause the complete extinction of all continental margin marine biodiversity.
- DLow ambient water temperatures in aphotic zones serve as the main factor shielding aragonite coral skeletons from natural acid corrosion.