Q: 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").
Fact1: the emission of sulfur dioxide causes acid rain, Fact2: Polluted rain is called acid rain ., Question: What causes pollution in rain? (A) sulfur dioxide (B) carbon dioxide (C) nitrogen (D) contamination (E) smog (F) hydrogen (G) fossil fuels (H) flooding
A:
A