If the mean deviation of the numbers $ 1, 1+d, 1+2d......1+100d$ from their mean is $255$, then the $d$ is equal to

Question

$\begin {array} {1 1} (A)\;10.0 & \quad (B)\;20.0 \\ (C)\;10.1 & \quad (D)\;20.2 \end {array}$