The answer is letter choice C
I didn't find a good reason, Coral organisms, called polyps, can live on their own, but are primarily associated with the spectacularly diverse limestone communities, or reefs, they construct. I would write this because of your passage. I would say that the answer is 3/4 but I would say 3 because he states about facts of sunlight to live. Hope this helps a little :)
- Joshyy <3
