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: Evolution occurs in response to a change in the environment., Fact2: Extinction is a natural part or the process of evolution., Question: What happens to an environment to cause extinction? (A) relocation (B) changes (C) rain (D) exposure (E) forces (F) wind (G) Pollution (H) discovery
A:
B