How are sponges and the coral in coral reefs similar? A. Both are a source of chemicals that may be used to fight human diseases, such as cancer.
B. Both release large amounts of oxygen into ocean waters, and the oxygen is eventually used by humans to breathe.
C. Both are widely found in deep, cold oceans as well as in warm, shallow waters.
D. Both are small ecosystems that do not have a heavy impact on other organisms.