If disease-causing tiny living cells have a negative impact on the body, then what can cause disease, and have a negative impact on the body?

Answer choices:
- Tiny living cells.
 - dead organisms
 - smoking tobacco
 - deoxyribonucleic acid
 - single-celled organisms
 - Body doubles.
 - Negative balance.
 - Crater impact.

 

 Tiny living cells.         