Detailed Instructions: 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: Molds and spores thrive in water-damaged furniture and carpets., Question: what has a negative impact on the respiratory system? (A) harmful substances (B) water-damaged carpets (C) a pathogens (D) lungs (E) density (F) oxygen (G) Something that causes allergies (H) some viruses
A:
B