What substance will displace the cupula during rotational equilibrium?

A) fluid within the semicircular canal
B) fluid within the utricle
C) the otoliths within the semicircular canal
D) the otoliths within the vestibule
E) fluid within the auditory tube

During rotational equilibrium, the fluid within the semicircular canal moves in response to the movement of the head. This movement displaces the cupula, which is the gelatinous structure within the canal that contains hair cells. The displacement of the cupula leads to depolarization or hyperpolarization of the hair cells and the generation of action potentials that are sent to the brain via the vestibular nerve.