Three blocks $\mathrm{A}, \mathrm{B}$, and $\mathrm{C}$ of equal mass $\mathrm{m}$ are placed one over the other, one on a smooth horizontal ground as shown in figure. Coefficient of friction between any two blocks of $\mathrm{A}, \mathrm{B}$ and $\mathrm{C}$ is $0.5$. What would be the maximum value of mass of block $D$ so that the blocks $A, B$ and $C$ move without slipping over each other?
(A) $3 \mathrm{~m}$
(B) $5 \mathrm{~m}$
(C) $6 \mathrm{~m}$
(D) $4 \mathrm{~m}$