$.$ Consider the IP block $198\mathrm{.}51\mathrm{.}100\mathrm{.}0/22$ allocated to a certain organization. They want to allocate subblocks to the following departments to satisfy their needs $(6$ points$)$ Department A has $60$ hosts. $$ Department B has $29$ hosts. $$ Department C has $12$ hosts. Solve the following problems: i$.$ Assign an appropriate subnet mask to each department. ii$.$ Specify the range of usable IP addresses $($i$.$e$.$ addresses that can be assigned to hosts or routers$)$ allocated to each department.