30 POINTS Refer to the Newsela article "Climate Change in Hawaii and U. S. Tropical Islands."
What is the author's purpose in mentioning coral reefs in the article?

A. to explain how climate change is damaging the delicate ecosystem in coral reefs

B. to suggest that algae and not climate change is responsible for the decline in coral reefs

C. to point out that coral reefs were already endangered before climate change

D. to illustrate how rising sea levels and coral reefs are creating climate change