Four of five are same in such a way that they form a group. Which of the following doesn’t belong to the group.

M and A are married to each other. M and X are not sitting in the inner square. So, M is sitting in the Outer square and A in inner square. N is not an immediate neighbour of O. N is not an immediate neighbour of O and doesn’t sit in inner square. O is married to Y who is sitting in the inner square. So, N and O are sitting in outer square. Y is sitting in inner square. So, from above information we know that M, X, N and O are sitting in outer square and A, Y, W and Z are sitting in inner square. Immediate neighbour of A is not male. W is not m female. So, A and W are not sitting together. By the above arrangements we get to know that X is married to W and is m female and N and O are male. The one who sits to the immediate right of O is not female. By this statement we know the positions of N and O. M is male. Among M and Z one of them is male. We know that M is male. So, Z is female.  O is married to Y.