$4$ A network administrator is adding a new LAN to a branch office. The new LAN must support $200$ connected devices. What is the smallest network mask that the network administrator can use for the new network?

$255\mathrm{.}255\mathrm{.}255\mathrm{.}224$

$255\mathrm{.}255\mathrm{.}255\mathrm{.}0$

$255\mathrm{.}255\mathrm{.}255\mathrm{.}248$

$255\mathrm{.}255\mathrm{.}255\mathrm{.}240$