A network administrator wants to use a subnet mask containing $62$ usable adaresses.

Which of the following subnet masks should the administrator use?

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

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

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

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