Given the task definition and input, reply with output. 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: Most carcinogens cause cancer by producing mutations in DNA., Fact2: Lung cancer is the deadliest of all cancers., Question: what cause production of mutations in DNA of areas such as lungs (A) Damages them (B) the environment (C) carcinogens (D) cigarettes (E) rays or beams (F) smoking tobacco (G) smoking (H) Pollution
C