Peristaltic waves are
a. segmental regions of the gastrointestinal tract
b. churning movements of the gastrointestinal tract
c. pendular movements of the gastrointestinal tract
d. waves of muscular contractions that propel contents from one point to another

Option (D).

Explanation:

Peristaltic movements are involuntary movement occur due to the longitudinal and circular muscle.Peristaltic waves helps in the passage of food from one point to another during the process of digestion.

Peristaltic waves occur mainly due to muscular contraction. These contractions propel the contents from one location to another. These waves occur in stomach, intestine and esophagus.

Thus, the correct answer is option (D).

weathering is the answer.