You will be given a definition of a task first, then some input of the task.
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").

Fact1: Evolution is a change in the characteristics of living things over time., Fact2: Evolution relies on random chance acts to cause mutations., Question: What causes changes in characteristics of living things over time? (A) mutations (B) science (C) parents (D) environment (E) light energy (F) news (G) alleles (H) animals
Output:
A