You are presented with the question "What is one way animals learn to behave?" and the following answer choices: 
- garbage
 - Generating heat
 - Space travel
 - running and lifting
 - Time and energy
 - exercise
 - money
 - Riding a bike

Now knowing that playing is one way mammals and other animals learn how to behave and involvement in play takes time and energy, choose the best answer.


 

     Time and energy    