Which subnet mask would be used if $5$ host bits are available?

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

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

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

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