A manager wants to build $3-$sigma $x-$bar control limits for a process. The target value for the mean of the process is $10$ units, and the standard deviation of the process is $6.$ If samples of slze $9$ are to be taken, what will be the upper and lower control limits$,$ respectively?

A$)-8$ and: $28$

B$)16$ and $4$

C$)12$ and $8$

D$)4$ and $16$

E$)8$ and ${12}^2$