Alice has been instructed to create an IPv$4$ network with $8$ subnets and $30$ hosts per subnet. She has been assigned a Class $C$ network address. Which of the following subnet masks will she have to use?

$255\mathrm{.}255\mathrm{.}255\mathrm{.}128$

$255\mathrm{.}255\mathrm{.}255\mathrm{.}192$

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

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