The Eardrum Is A

The eardrum is a:

A) part of the outer ear that vibrates when sound waves hit it.
B) thin membrane leading to the inner ear.
C) coiled tube in the inner ear filled with fluid that vibrates in response to sound.
D) vibrating structure that runs through the center of the cochlea, dividing it into an upper chamber and a lower chamber, and contains sense receptors for sound.