The Symbiotic Dinoflagellates That Live in the Tissues of Coral

The symbiotic dinoflagellates that live in the tissues of coral polyps ____.

A) provide carbon dioxide and phosphates for the polyps
B) feed on the tissues of the polyps and are dangerous parasites
C) are the main cause of coral bleaching, and are threatening the reefs of the world
D) provide additional nourishment and oxygen to the polyps through photosynthesis