You are presented with the question "What requires energy?" and the following answer choices: 
- trees staying in place
 - animals with backbones
 - Veins and arteries.
 - statues not moving
 - some invertebrates
 - rocks remaining still
 - power stations
 - animals running

Now knowing that an animal requires energy to move and and as they move or run, their legs barely move, choose the best answer.


 

        animals running 