digestive and endocrine muscular and skeletal reproductive and excretory circulatory and digestive
I gave my students this multiple choice question: Running to escape danger is an action that requires the nervous system to coordinate the interaction of which two body systems?

Only one answer is correct among these 4 choices:
- digestive and endocrine
- muscular and skeletal
- reproductive and excretory
- circulatory and digestive

Could you tell me which one is correct?

muscular and skeletal