Which of the following is a class A IPv$4$ address?

a$.118\mathrm{.}20\mathrm{.}210\mathrm{.}254$

b$.183\mathrm{.}16\mathrm{.}17\mathrm{.}30$

c$.215\mathrm{.}16\mathrm{.}17\mathrm{.}30$

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