Given the task definition and input, reply with output. 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: gases from burning coal and oil dissolving in water in the atmosphere causes acid rain, Fact2: Acid rain is harmful rain., Question: what are gases from burning coal and oil dissolving in water in the atmosphere? (A) harmful (B) deadly (C) h2o (D) helpful (E) dangerous (F) vehicles (G) green (H) toxins
A