D, E, F, G, M, N and O are sitting around a circular table, facing the centre of the table. N sits to the immediate left of D. G sits to the immediate left of E. E sits second to the left of O. F sits third to the left of D. Who sits fourth to the right of M? 

Given - D, E, F, G, M, N and O are sitting around a circular table, facing the centre of the table.
N sits to the immediate left of D.
G sits to the immediate left of E.
E sits second to the left of O.
F sits third to the left of D.

From the given information seating arrangement will be:

So, O sits fourth to the right of M.

Thus, the correct option is: (b)