Instructions: 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").
Input: Fact1: a windmill converts wind energy into electricity primarily by using mechanical energy, Fact2: Mechanical energy is the energy of moving objects., Question: what does a windmill primarily use to convert wind energy into electricty? (A) matter vibrating (B) stored energy (C) solar power (D) batteries (E) Movement of an air mass (F) heat is produced (G) energy of moving objects (H) Something to move
Output:
G