What is the host address for a machine with the IP address of $128\mathrm{.}30\mathrm{.}45\mathrm{.}15$ with a mask of $255\mathrm{.}255\mathrm{.}0\mathrm{.}0?$

Question $39$ options:

$128\mathrm{.}30\mathrm{.}0\mathrm{.}0$

$128\mathrm{.}30\mathrm{.}45\mathrm{.}15$

$15$

$45\mathrm{.}15$