The Primary Function of the Cricopharyngeus Muscle at the Pharyngeal

The primary function of the cricopharyngeus muscle at the pharyngeal end of the esophagus is to ___________________________________.

A) assist in the movement of food through the esophagus
B) prevent the regurgitation of stomach contents
C) prevent the aspiration of blood
D) assist in blood flow
E) prevent the swallowing of air