Detailed Instructions: 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").
Q: Fact1: Corals form large colonies in shallow tropical water., Fact2: Water is shallow at the shore with gradual deepening., Question: Where do corals form large colonies? (A) Mars (B) new World (C) Sediment (D) shoreline (E) environment (F) Absorb light (G) loose soil (H) polyps
A:
D