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: Mating is generally preceded by courtship., Fact2: Many birds perform elaborate courtship dances., Question: What do many birds do before they mate? (A) migrate (B) Sleep (C) drink (D) Dance (E) sweat (F) Eat (G) Die (H) bite
A:
D