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: Mutations may change the structure of a chromosome or just change a single nucleotide., Fact2: Mutations in genes on the Y chromosome have been implicated in male genetic infertility., Question: What does changes in the structure of the Y chromosome do? (A) reproduce (B) Male infertility (C) harm them (D) bending light rays (E) It expands (F) allow growth (G) Plant growth is reduced (H) Damages them
Output:
B