Four from the following five are related in a certain way and hence form a group. Find the one who doesn’t belong to that group.

Study the following information carefully and answer the questions below. Eight employees A, B, C, D, M, N, O and P of a company are sitting around a rectangular table and facing away from the center of the table but not necessarily in the same order. Four of them are seated at the corners of the table and four are seated in the sides of the table. M is sitting 3rd to the left of the one who is sitting 2nd to the right of
C. Only three persons are sitting between D and O. P is an immediate neighbour of either M or
C. Person who is sitting opposite to A, is sitting 2nd to the right of O. N is sitting 2nd to the right of
B. N is neither sitting opposite to C nor sitting in the corner of the table.