A levelling is carried out to establishing the Reduced Levels (RL) of point R with respect to the Bench Mark (BM) at P. The staff readings taken are given below:

$\begin{array}{|c|c|c|c|c|} \hline \textbf{Staff } \\ \textbf{Station} & \textbf{BS} & \textbf{IS} & \textbf{FS} & \textbf{RL} \\ \hline P & 1.655 \: m & {} & & 100.000 \: m \\ \hline Q & -0.950 \: m & { } & -1.500 \: m & { } \\ \hline R & { } & { } & 0.750 \: m & \text{?} \\ \hline \end{array}$

If $RL$ of $P$ is $+100.000$ m, then $RL$ (in m) of $R$ is

1. $103.355$
2. $103.155$
3. $101.455$
4. $100.355$