A child hanging upside down from a tree takes a bite from a candy bar. They manage to chew the candy and swallow it successfully. What prevents the bolus from entering the upper part of the nasopharynx?
A. The most anterior section of the nasopharynx is only connected to the oropharynx by small ducts, so the bolus cannot enter it.
B. During the swallowing reflex, the tongue presses against the soft palate and forces the nasal region of the nasopharynx shut.
C. Muscles immediately pull the pharynx upward toward the bolus in the swallowing reflex and suck it from the back of the tongue.
D. The posterior part of the tongue and the anterior section of the pharynx also undergo peristalsis, so the food is immediately pushed downward.
Answer: B
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