providing structural support to muscles carrying oxygen to cells getting energy from food sending messages to the brain
I gave my students this multiple choice question: Mr. Mendoza's class studied different body systems. What is an important function of the circulatory system?

Only one answer is correct among these 4 choices:
- providing structural support to muscles
- carrying oxygen to cells
- getting energy from food
- sending messages to the brain

Could you tell me which one is correct?

carrying oxygen to cells