Q: 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: skin is used for breathing air by frogs, Fact2: An apathetic frog is probably a sick frog., Question: What largest organ can cause sickness? (A) Heart (B) lungs (C) immune (D) germs (E) mold (F) Skin (G) Liver (H) Stomach
A:
F