If the volume of a sphere is increasing at the rate of $12 \mathrm{c}. \mathrm{c}. / \mathrm{sec}$, then the rate (in $\mathrm{sq}. \mathrm{cm} / \mathrm{sec}$ ) at which its surface area is increasing, when the diameter of the sphere is 12 cm is

• A

  $2$
• B

  $3$
• Correct answer
  C

  $4$
• D

  $6$

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