In a fixed$-$point representation system that uses $2$ bits for the integer part and $3$bits for the fractional part, what is the round$-$off error when representing the number$3\mathrm{.}75?$

$($A$)-0\mathrm{.}0625$

$($B$)0$

$($C$)0\mathrm{.}125$

$($D$)-0\mathrm{.}125$