occurs when the longitudinal, circular, and diagonal muscles that surround the organ forcefully push, churn, and mix the contents of the stomach with the gastric juices.

The correct answer is Peristalsis.

Explanation:

Peristalsis occurs when the longitudinal, circular, and diagonal muscles that surround the organ forcefully push, churn and mix the contents of the stomach with the gastric juices.

Peristalsis, are all those movements resulting from the contraction of the digestive tract through its different muscle layers which transport the contents from the stomach to the anus, thus intervening in the digestion process