Passage

During the summer in the Arctic Ocean, sea ice has been melting earlier and faster, and the winter freeze has been coming later. In the last three decades, the extent of summer ice has declined by about 30 percent. The lengthening period of summer melt threatens to undermine the whole Arctic food web, atop which stand polar bears.

Question

CSATEasyPrelims 2017Comprehension

Which among the following is the most crucial message conveyed by the above passage?

Explanation

Option A is incorrect. This indicates changes in the climate and how they are affecting the environment, but it does not directly relate to the survival of polar bears or food chains.

Option B is incorrect. This highlights the ongoing climate change in the Arctic, which is directly linked to changes in the environment where polar bears live. However, it doesn't provide a direct statement about polar bear survival but suggests a potential threat to their habitat.

Option C is incorrect. This directly ties the decline in ice to a threat to the Arctic food web, and polar bears are mentioned at the top of this food chain, indicating their potential endangerment due to climate change.

Option D is correct. It directly addresses the potential threat to polar bears' survival due to changes in their environment caused by climate change.