Temperatures have risen nearly five times as rapidly on the Western Antarctic Peninsula than the global average over the past five decades. Researchers have now found that melting glaciers are causing a loss of species diversity among benthos in the coastal waters off the Antarctic Peninsula, impacting an entire seafloor ecosystem. They believe increased levels of suspended sediment in water to be the cause of the dwindling biodiversity in the coastal region.

Correct Option (C)

Assumptions 2 and 3 are valid based on the provided passage.

• Assumption 2: The passage states that melting glaciers lead to increased levels of suspended sediment in the water. This process, where suspended particles settle, directly contributes to seafloor sedimentation. Given that glacier melt is a consequence of rising temperatures attributed to global warming, it is a valid inference that global warming can indirectly lead to seafloor sedimentation in specific regions.
• Assumption 3: The passage explicitly links melting glaciers to a "loss of species diversity among benthos in the coastal waters" and notes its impact on "an entire seafloor ecosystem." This directly supports the assumption that melting glaciers can reduce marine biodiversity in affected areas.

Incorrect Options:

• Assumption 1: The passage specifies that temperatures have risen nearly five times as rapidly on the Western Antarctic Peninsula compared to the global average. This observation pertains to a particular glacial region. The passage does not provide a basis to generalize that all regions containing glaciers warm faster than all other non-glacial regions globally due to global warming.