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: a breathing mask is used for keeping harmful particles from entering the respiratory system, Fact2: Sulfate particles irritate the lower respiratory system., Question: What is one thing a breathing mask can protect you from? (A) sulfate particles (B) enormous damage to homes (C) massive damage (D) too much air (E) Dehydration (F) electromagnetic radiation (G) choking on food (H) influenza
Output:
A