Definition: 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: carpooling decreases the amount of cars used to travel to a place, Fact2: Arrange carpools to conserve fuel., Question: Decreasing what during travel likely conserves fuel? (A) the energy of the car (B) air mass over Earth's surface (C) the amount of cars used (D) the size of the wheels (E) the amount of water used (F) kinetic energy (G) preventing heat transfer (H) energy usage
Output:
C