Read the following statements regarding the structure of the human ear and select the correct option.
Statement $I$: The tympanic membrane is covered with mucous membrane on the inner side,to the surface of which is attached the $1^{\text{st}}$ ear ossicle,namely the incus.
Statement $II$: Scala vestibuli and scala tympani are filled with perilymph and form a part of the cochlea.

• A
  Both statement $I$ and statement $II$ are correct.
• B
  Both statement $I$ and statement $II$ are incorrect.
• C
  Statement $I$ is correct but statement $II$ is incorrect.
• D
  Statement $I$ is incorrect but statement $II$ is correct.