Which of the following depicts zero overlap?
In option (a), as we can see, s-orbital is on z-axis, while p-orbital is on x-axis, therefore there is no overlapping. In option (b), one p-orbital is on x-axis while the other p-orbital is on y-axis, therefore there is no overlapping.
In case of (c) and (d),
Overlapping is possible because they are on same axis.