Given the task definition and input, reply with output. In this task, you are given two facts, and a multiple-choice question. Based on the given facts, answer the question with index of the correct option (e.g, "A").

Fact1: Coral reefs provide food and shelter to many ocean organisms., Fact2: Humans depend upon the life-support systems provided by the oceans., Question: What do coral reefs provide for humans? (A) Energy. (B) support (C) fuel (D) Energy (E) food (F) destruction (G) pain (H) body water
B