Which of these is a valid Class A address?

A $,191\mathrm{.}10\mathrm{.}0\mathrm{.}1$

B $,127\mathrm{.}10\mathrm{.}0\mathrm{.}1$

C

D $,,126\mathrm{.}10\mathrm{.}0\mathrm{.}1$