Answer
The correct answer is:
(d) Both (a) and (c)
Work Step by Step
$P_1$ and $P_5$ are both open to the atmosphere, so both of these points are at atmospheric pressure.
$P_3$ and $P_4$ are both the same height from the bottom with the volume below filled with the same fluid. Therefore these two points have equal pressure.
The correct answer is:
(d) Both (a) and (c)
