Given the task definition and input, reply with output. 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: measuring the hardness of minerals requires scratching those materials, Fact2: Moh's scale is used to describe a mineral's hardness., Question: What is done to a mineral to determine its place on the Moh's scale? (A) scratch (B) keratin (C) Laboratory (D) classified (E) treatment (F) surveyor (G) percents (H) as a base
A