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: unequal heating of Earth 's surface by the Sun causes global wind patterns, Fact2: Wind is air that is moving across the surface of Earth., Question: What does uneven heating of earth's crust cause? (A) force (B) harm (C) Rain (D) Snowstorm (E) cracks (F) Wind (G) Injury (H) Hurricanes
F