A theodolite was set up at a station $P$. The angle of depression to a vane $2 \mathrm{~m}$ above the foot of a staff held at another station $\mathrm{Q}$ was $45^{\circ} .$ The horizontal distance between stations $\mathrm{P}$ and $\mathrm{Q}$ is $20 \mathrm{~m}$. The staff reading at a benchmark $\mathrm{S}$ of RL $433.050 \mathrm{~m}$ is $2.905 \mathrm{~m}$. Neglecting the errors due to curvature and refraction, the RL of the station $\mathrm{Q}($ in $\mathrm{m}),$ is
(A) 413.050
(B) 413.955
(C) 431.050
(D) 435.955
A theodolite was set up at a station $P$. The angle of depression to a vane $2 \mathrm{~m}$ above the foot of a staff held at another station $\mathrm{Q}$ was $45^{\circ} .$ The horizontal distance between stations $\mathrm{P}$ and $\mathrm{Q}$ is $20 \mathrm{~m}$. The staff reading at a benchmark $\mathrm{S}$ of RL $433.050 \mathrm{~m}$ is $2.905 \mathrm{~m}$. Neglecting the errors due to curvature and refraction, the RL of the station $\mathrm{Q}($ in $\mathrm{m}),$ is
(A) 413.050
(B) 413.955
(C) 431.050
(D) 435.955