In a cubic close packed structure, fractional contributions of an atom at the corner and at the face in the unit cell are, respectively:

• Correct answer
  A

  $1 / 8$ and $1 / 2$
• B

  $1 / 2$ and $1 / 4$
• C

  $1 / 4$ and $1 / 2$
• D

  $1 / 4$ and $1 / 8$

Hence, the correct answer is option: 'A'.