Fact 1: Lung cancer is most often caused by exposure to tobacco smoke. Fact 2: Many patients with lung cancer also have emphysema. Given the two facts above, emphysema is often cause by exposure to:?

pick from the following. (A). high temperature (B). fog (C). Greenhouse gasses (D). rays or beams (E). hot steam (F). tobacco smoke (G). Pollution (H). incendiary people
Answer:
(F).