TOEFL Listening: TPO-TOEFL听力TPO - 94S7Y7CTQ121H7U7R$

Why does the professor mention that coral reefs support more than 4,000 species of fish? A. To find out what students know about tropical fish B. To contrast two types of ocean environments C. To imply that there may be species in the Southern Ocean that have not been discovered yet D. To imply that there may be fossil evidence of coral reefs in the Southern Ocean