Fact 1: Lung cancer is most often caused by exposure to tobacco smoke.

Fact 2: Secondhand smoke is also known as Environmental Tobacco Smoke.

Given the two facts above, answer the question "What can be caused by secondhand smoke?" with the following options: 
- clean air
 - fresh scent
 - Toxicity
 - Pollution
 - negative
 - lung cancer
 - healthy lungs
 - Dehydration


 

      lung cancer   