The set _{$\text{S={1,2,3,}\mathrm{......}\text{12} }$} is to be partitioned into three sets A, B, C of equal size. Thus_{$\text{A}\cup \text{B}\cup \text{C = S, A}\cap \text{B=B}\cap \text{C=C}\cap \text{A=}\varphi$} . The number of ways to  partition is

• A

  _{$\frac{12!}{{(4!)}^3}$}

• B

  _{$\frac{12!}{3!(3!)4}$}

• C

  $\frac{12!}{{(4!)}^3.3!}$

• D

  _{$\frac{12!}{{(3!)}^4}$}