the intestine, with squeezing. the mouth, with chewing and saliva. the stomach, with churning and acid. the esophagus, with pushing towards the stomach.
I gave my students this multiple choice question: In humans, the digestion process begins in

Only one answer is correct among these 4 choices:
- the intestine, with squeezing.
- the mouth, with chewing and saliva.
- the stomach, with churning and acid.
- the esophagus, with pushing towards the stomach.

Could you tell me which one is correct?

the mouth, with chewing and saliva.