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: riding a bike does not cause pollution, Fact2: Bikes are good for exercise and produce no pollution., Question: What can you ride to get good exercise and avoid producing harmful gases? (A) cows (B) bike (C) stairmaster (D) cycles (E) bus (F) trolley (G) Lift (H) goats
A:
B