Fact 1: An animal requires stamina to succeed at physical activities.

Fact 2: Bears are common but elusive animals.

Given the two facts above, answer the question "What requires stamina to succeed at physical activities?" with the following options: 
- rocks
 - rainbows
 - running
 - tigers
 - waterfalls
 - pigeons
 - humans
 - bears


 

        bears 