Here's a problem to solve: Which best describes two organ systems working together to help maintain homeostasis?

Among the 4 following options, which is the correct answer?

- A: The reproductive organs produce sex cells.
 
- B: The nerves carry signals from the eye to the brain.
 
- C: The bones and muscles of the hand work together to grip a pencil.
 
- D: The muscles of the chest tighten to push carbon dioxide out of the lungs.
 