Fact 1: Cancer cells divide more often than normal cells, and grow out of control.

Fact 2: Chemotherapy and radiotherapy target the rapidly dividing cancer cells.

Given the two facts above, answer the question "What targets cells that grow out of control?" with the following options: 
- smoking cigarettes
 - Other cells
 - radiation
 - killing insects
 - The brain
 - massive damage
 - Bacteria
 - Chemotherapy


 

        Chemotherapy 