In the given figure, if quadrilateral PQRS circumscribes a circle, then PD + QB =

We know that tangents drawn to a circle from the same external point will be equal in length.

Therefore,

PD = PA …… (1)

QB = QA …… (2)

Adding equations (1) and (2), we get,

PD + QB = PA + QA

By looking at the figure we can say,

PD + QB = PQ

Therefore option (a) is the correct answer.