Four of the following are alike in a certain way, find out which of the following do not form a part of the group?

Study the following information carefully and answer the given questions The family consists L, M, N, O, P, Q, R and S was sitting around a circular table facing the centre. Some of the information about their seating arrangement is given. (i) N, one of the sons of R, sits exactly opposite R and is an immediate neighbour of his mother. (ii) N’s sister Q is exactly opposite her husband O and Q is an immediate neighbour of S. (iii) N’s niece. M, sits third to the left of her grandfather. (iv) P, who has no child is a male member while N and M are the only unmarried members of the family. (v) No couple sits together. N’s sister-in-law. S, sits second to the right of her husband