Fact 1: Population size influences the chances of a species surviving.

Fact 2: Each species lasts for a time, sometimes surviving to the present and sometimes going extinct.

Given the two facts above, answer the question "what influences the chances of going extinct?" with the following options: 
- cloud cover
 - Population size
 - Pollution
 - Pesticides
 - rainfall
 - risky population
 - Climate change
 - the environment


 

  Population size       