For a Class C IPv$4$ address, what is the correct default subnet mask value, specified as either a dotted decimal address or a CIDR value? $($Choose all that apply.$)$

a$.$ C::$/24$

b$./24$

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

d$.255\mathrm{.}255\mathrm{.}256\mathrm{.}0$

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