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

Fact 2: Mutations are changes in the DNA sequence.

Given the two facts above, answer the question "Most carcinogens cause cancer by producing changes in what?" with the following options: 
- harmful substances
 - Chlorophyll
 - the skin
 - the eyes
 - organs
 - layers of fat
 - DNA sequence
 - alleles


 

       DNA sequence  