Select the letter-cluster that can replace the question mark (?) in the following series.
GOAL, IMCJ, KKEH, MIGF, ?
Answer & explanation
Correct answer: option 4

Explanation:
GOAL, IMCJ, KKEH, MIGF, ?
The logic followed here is :
G → (+2) → I → (+2) → K → (+2) → M → (+2) → O
O → (-2) → M → (-2) → K → (-2) → I → (-2) → G
A → (+2) → C → (+2) → E → (+2) → G → (+2) → I
L → (-2) → J → (-2) → H → (-2) → F → (-2) → D
So, the letter-cluster that replaces the (?) to complete the series is "OGID"