If 'A $ B' means 'A is father of B', 'A # B' means 'A is daughter of B', 'A @ B' means 'A is sister of B', then how is P related to S in P @ Q $ R # S? MCQ with Answer and Explanation

P sister of Q, Q father of R, R daughter of S. So S is parent of R and Q (since Q father of R, S spouse of Q). P is sister of Q, so P is sister-in-law of S or aunt of R. Relation of P to S is sister-in-law, not in options.