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: Sweat wets the skin, and when it evaporates, it cools the body., Fact2: Perspiration There are about 2 million sweat glands in the average human body., Question: What wets the skin, and when it evaporates, it cools the body? (A) heat energy (B) acetic acid (C) Air conditioner (D) salt and water. (E) Skin oil (F) water vapor (G) Perspiration (H) A towel
G