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: riding a bike does not cause pollution, Fact2: Carbon monoxide is, of course, an air pollutant., Question: What is not released after riding a bike? (A) carbon monoxide (B) harmful substances (C) fossil fuels (D) heat energy (E) one celled organisms (F) hard outer covering (G) layers of fat (H) Pituitary gland
A:
A