Observe the following statements regarding the purification of bauxite and select the correct answer.
$(I)$ During the $Hall$ process,silicon is removed in the form of vapor.
$(II)$ Bauxite containing $Fe_2O_3$ impurities is purified by the $Bayer$ process.
$(III)$ $AlN$ is formed during the $Serpeck$ process.

• A
  $(I), (II)$ and $(III)$ are correct.
• B
  Only $(I)$ and $(II)$ are correct.
• C
  Only $(I)$ and $(III)$ are correct.
• D
  Only $(II)$ and $(III)$ are correct.