Instructions: 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: breaking apart rocks can cause debris, Fact2: Sledge hammers can be used to break especially hard ledges of rock., Question: What can be used to make debris? (A) erosion (B) rivers (C) a hammer (D) heat (E) wind (F) water pump (G) c-clamp (H) screwdriver
Output:
C