Fact 1: Most carcinogens cause cancer by producing mutations in DNA.

Fact 2: Smoke is full of carcinogens.

Given the two facts above, answer the question "What can cause cancer by producing mutations in DNA?" with the following options: 
- maples
 - PDAs
 - A drug.
 - copper
 - coal
 - CO 2
 - smoke
 - sponges


 

       smoke  