You are presented with the question "what makes it possible for an animal to move?" and the following answer choices: 
- Limbs
 - four limbs
 - digestion
 - stamina
 - motility
 - magnets
 - radiation
 - weather

Now knowing that when an animal moves , chemical energy is converted to mechanical energy and digestive processes include mechanical, chemical and enzymatic mechanisms, choose the best answer.


 

   digestion      