What is unusual about the muscular external of the pharynx?
a. it is absent
b. it contains 3 layers instead of 2
c. the longitudinal layer consists only of a narrow band
d. the positions of the circular and longitudinal layers are reserved

A)  it is absent

Explanation:

Unusual about the muscular external of pharynx are that it is not absent as muscular external because it is the important function for protecting the wall of pharyngeal in the pharynx. During the swallowing these muscles acts as a shorten and the wider in the pharynx. Pharynx is the muscular tube which helps in connecting the nasal cavity.

communicate with the patient and explain every step before proceeding to do so