the respiratory system the digestive system the nervous system the skeletal system
I gave my students this multiple choice question: Different systems of the human body perform different functions. Which system takes oxygen from the air to be moved by the circulatory system?

Only one answer is correct among these 4 choices:
- the respiratory system
- the digestive system
- the nervous system
- the skeletal system

Could you tell me which one is correct?

the respiratory system