make oxygen. release energy. digest nutrients. cause movement.
I gave my students this multiple choice question: There are different kinds of muscles in the human body. Each muscle is formed from a group of cells that works together. The main function of a group of muscle cells is to

Only one answer is correct among these 4 choices:
- make oxygen.
- release energy.
- digest nutrients.
- cause movement.

Could you tell me which one is correct?

cause movement.