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: pathogens can cause disease, Fact2: This suggests the pathogen may be moved through the air somehow., Question: How can diseases be trasferred? (A) Getting a vaccine (B) By studying it (C) radiography (D) In the air (E) Looking at it too closely (F) anemia (G) chickenpox (H) influenza
D