A weight $W$ is suspended from a trolley travelling along a rail. While the trolley moves horizontally by a distance $p$, it at the same time lifts the weight through a height $q$. Hence, the weight is displaced a distance $r$ from X to Y. It begins and ends at rest. What amount of work is done on the weight in this process?
- A$Wp$
- B$W(p + q)$
- C$Wq$
- D$Wr$