Definition: 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").
Input: Fact1: Corals form large colonies in shallow tropical water., Fact2: Coral is the calcite shell of the coral animal., Question: what forms large colonies in shallow tropical water? (A) Most plants (B) passenger pigeons (C) orchids (D) honeybees (E) calcite shells (F) trout (G) sharks (H) humans
Output:
E