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: a mold spore has a negative impact on the respiratory system, Fact2: Major components of the respiratory system are the lungs, trachea, nose, and the cell., Question: What has a negative impact on the lungs? (A) unpolluted air (B) healthy atmosphere (C) mold spore (D) smoking (E) disease (F) influenza (G) clean air (H) A virus
A:
C