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: measuring the hardness of minerals requires scratching those materials, Fact2: Diamonds are so hard because of the shape of a diamond's structure., Question: What can you scratch to measure? (A) stoma (B) bone (C) yardsticks (D) diamonds (E) rulers (F) distance (G) hairs (H) measuring tape
Output:
D