Detailed 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").
Q: Fact1: carpooling decreases the amount of cars used to travel to a place, Fact2: Cars and gasoline-burning engines are large sources of emissions., Question: What can help decrease emissions? (A) power (B) exercise (C) Carpooling (D) Flying on airplanes (E) Having children (F) Eating red meat (G) green manures (H) electricity
A:
C