Four messages band limited to $\text{W, W, 2W}$ and $\text{3W}$ respectively are to be multiplexed using $\text{Time Division Multiplexing (TDM)}.$ The minimum bandwidth required for transmission of this $\text{TDM}$ signal is
- $\mathrm{W}$
- $3 \mathrm{W}$
- $6 \mathrm{W}$
- $7 \mathrm{W}$