Fact 1: Behaviors that improve fitness increase through natural selection.

Fact 2: Fitness traits relate to an animal s ability to survive and reproduce.

Given the two facts above, answer the question "behaviors increase through what that improve traits of animal's ability to survive" with the following options: 
- competition
 - hunting
 - biological diversity
 - the environment
 - eating
 - produce offspring
 - natural selection
 - grooming


 

       natural selection  