Answer (b) The stapes of the middle ear transmits sound vibrations to the oval window.
Work Step by Step
The three ossicles of the middle ear are the malleus, incus, and stapes. The malleus (hammer) is fixed to the tympanic membrane (ear drum); the incus( anvil) is in the middle and the base of the stapes (stirrup) fits into the oval window. The ossicles transmit the vibrations of the ear drum to the oval window. The vibrations of the oval window sets the fluids of the inner ear ( perilymph and endolymph) in motion, which motion excites the hearing receptors.