Answer:
Structure that connects the middle and inner ear and allows vibrations to pass into the Cochlea is oval window.
Explanation:
The oval window is a membranous structure in relation to the stirrup, the ossicle of the middle ear, whose function is to transmit the vibrations it receives to the inner ear, specifically to the cochlea.
Sound coming from outside produces vibrations received by the eardrum, and transmits these vibrations to the hammer, anvil and stirrup, which also makes the oval window vibrate. Vibrations that reach the cochlea mobilize the liquid that is there, which translates vibrations into nervous impulses.
One can say the oval window is the separation between middle and inner ear.
Other options are not correct because: