Molal depression constant for a solvent is $4.0\mathrm{ }\mathrm{K}\mathrm{ }\mathrm{k}\mathrm{g}\mathrm{ }\mathrm{m}\mathrm{o}{\mathrm{l}}^{-1}.$ The depression in the freezing point of the solvent for $0.03\mathrm{m}\mathrm{o}\mathrm{l}\mathrm{k}{\mathrm{g}}^{-1}$ solution of ${\mathrm{K}}_2\mathrm{S}{\mathrm{O}}_4$ is:
(Assume complete dissociation of the electrolyte)

• Correct answer
  A

  $0.36\mathrm{ }\mathrm{K}$
• B

  $0.24\mathrm{ }\mathrm{K}$
• C

  $0.18\mathrm{ }\mathrm{K}$
• D

  $0.12\mathrm{ }\mathrm{K}$

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