Which of the following letter-number clusters will replace the question mark (?) in the given series to make it logically complete?
GIM 8, HJN 11, IKO 14, JLP 17, ?

​GIM 8, HJN 11, IKO 14, JLP 17, ?

Logic: ​Each letter in the cluster increases by 1 alphabetically, and the number increases by 3 in each step.

1st letter: G +1→ H, H +1 → I, I +1→ J, J +1 → K

2nd letter: I +1 → J, J +1 → K, K +1 → L, L +1→ M

3rd letter: M +1→ N, N +1→ O, O +1→ P, P +1 → Q 

Number: 8 +3 → 11, 11 +3 → 14, 14  +3 → 17, 17 + 3 = 20

So, the next term is: KMQ 20

Thus, the correct option is: (b)