Which results in mechanical digestion in the stomach ? ( science )
A: contractions that mix and chum the food
B: waves of smooth muscle that push the food
C: hydrochloric acid that kills bacteria in food
D: pepsin that breaks down proteins into amino acids

Not participating family bbq, go to university or college without scholarship, not getting a or a+.

Bmust be the answer, as technically all organs move, so a is incorrect. all organs are made of different types of cells, so that isn’t a problem, so c is also incorrect. human hearts are very similar to many other animals’ hearts, so d is also incorrect, yet the heart is made of muscle, which is hard to grow in the lab so it would be correct to say b