Three letter-clusters have been given, out of which three are alike in some manner and one is different. Select the odd one.

Logic: There are option A, C, D following the same logic (+2, +3) except B.

Option (a): BDG =  B + 2 = D, D + 3 = G.

Option (b): MOQ = M + 2 = O, O + 2 = Q.

Option (c): JLO = J + 2 = L, L + 3 = O.

Option (d): RTW = R + 2 = T, T + 3 = W.

So, the correct odd one out is MOQ

Thus, the correct option is (b) MOQ.