Which bone is in contact with the $fenestra \text{ } ovalis$?

The internal ear in mammals is responsible for:

The Eustachian tube is associated with the .....

$P$ is a continuous tubular structure. Inside these tubes, $Q$ is arranged.
$\quad\quad\quad P \quad\quad\quad Q$
$(A)$ $Scala \text{ vestibuli} \quad$ $Scala \text{ media}$
$(B)$ $Scala \text{ media} \quad$ $Scala \text{ tympani}$
$(C)$ $Scala \text{ tympani} \quad$ $Scala \text{ media}$
$(D)$ $Scala \text{ media} \quad$ $Scala \text{ vestibuli}$

The $Scala$ $media$ is a part of:

The vibrations of the sound waves finally open into the .........