It produces new cells to carry oxygen. It produces chemicals to regulate growth. It produces antibodies to fight bacteria. It produces electrical signals to control the body.
I gave my students this multiple choice question: A science teacher is discussing the immune system with his class. Which statement should the teacher make about this system?

Only one answer is correct among these 4 choices:
- It produces new cells to carry oxygen.
- It produces chemicals to regulate growth.
- It produces antibodies to fight bacteria.
- It produces electrical signals to control the body.

Could you tell me which one is correct?

It produces antibodies to fight bacteria.