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: For ranking the hardness of minerals, the Mohs scale is generally used., Question: A mineral is scratched in order to rank it on what scale? (A) stoma (B) properties (C) Mohs (D) attributes (E) eight (F) bone (G) scratch (H) weater
C