Answer the questions based on the information given below. There are seven persons M, N, O, P, Q, R and S in a family of three generations. There are only two married couples. There is no single parent in the family. M is the father-in-law of N. Q is the sister of P, who is unmarried. S is the grandmother of O, who is the nephew of P. R is the daughter of N. The gender of N and P is same. How is M related to O?