Harming an animal species has a negative impact on the population size of that species, and animals are harmed because of cosmetic testing. Given these facts, what has a negative impact on the population size of a species among the following options:
- Pesticides
 - influenza
 - steroids
 - liver cancer
 - cloudy and rainy weather
 - massive damage
 - cosmetic testing
 - killing insects


 

       cosmetic testing  