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: wind is used for producing electricity, Fact2: Wind is caused because of pressure differences in the atmosphere., Question: What can be used to produce electricity? (A) Something that generates electricity (B) an automobile engine (C) The bending of a ray of light (D) Something caused by pressure differences (E) that material's properties (F) energy of moving objects (G) series of enzyme-mediated reactions (H) Faulting of rocks in the crust
A:
D