Fact 1: Aggression is behavior that is intended to cause harm or pain.

Fact 2: Also, pain is an excellent deterrent.

Given the two facts above, answer the question "What can be a deterrent?" with the following options: 
- sunlight
 - fur seals
 - crocodiles
 - change
 - tail fins
 - aggression
 - herbicide
 - hope


 

      aggression   