What will come in place of question mark (?) in the following series

BCD, CEG, DGJ, ?, FKP

Given: BCD, CEG, DGJ, ?, FKP

Logic: Each first letter is increase by 1, Each second letter is increase by 2 and Each third letter is increase by 3. 

For the first letter: B → C → D → ? →F

B + 1 = C, C + 1 = D, D + 1 = E, E + 1 = F

For the second letter: C → E → G → ? → K

C + 2 = E, E + 2 = G, G + 2 = I, I + 2 = K

For the third letter: D → G → J → ? → P

D + 3 = G, G + 3 = J, J + 3 = M, M + 3 = P

So, EIM is missing term.

Thus, the correct answer is (b).