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: Earth 's magnetic patterns are used for finding locations by animals that migrate, Fact2: Bird migration is common., Question: Earth 's magnetic patterns are used for finding locations by which creatures? (A) animals (B) Frogs (C) bats (D) birds (E) dogs (F) humans (G) horses (H) insects
Output:
D