Correct option is B
Given:
S is facing R, which means they are sitting opposite each other.
R is to the left of A and to the right of P. This places R between A and P.
A is to the left of D, so A is sitting between R and D.
Y is to the left of P, so Y is sitting between P and someone else.
From the above given information following seating arrangement can be drawn-

After D exchanges his seat with Y and P exchanges his seat with R then the diagram-

From the above seating arrangement S is sitting to the left of D.
Thus, the correct answer is (b) S.