Which of the Following Best Describes the Muscular Actions of Digestion

Which of the following best describes the muscular actions of digestion?

A) Peristalsis begins in the stomach upon the initiation of the swallowing reflex.
B) Contraction and relaxation along the jejunum is enhanced by a third layer of diagonal muscles.
C) Segmentation along the intestines allows momentary reversal of the movement of intestinal contents.
D) Relaxation of the rectal sphincter muscles prevents the continuous elimination of stool.