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").
Q: Fact1: being burried under soil and mud changes peat into coal through extreme heat and pressure in a swamp over a long period of time, Fact2: Most coal is fossil peat., Question: What is coal made out of? (A) heat (B) rocks (C) fossils (D) water (E) trees (F) energy (G) power (H) calcite
A:
C