Select the letter-cluster from among the given options that can replace the question mark (?) in the following series.
ABCD, YZEF, WXGH, UVIJ, ?
Answer & explanation
Correct answer: option 1

Explanation:
ABCD, YZEF, WXGH, UVIJ, ?
The logic followed here is :
A→ (-2) → Y → (-2) → W → (-2) → U → (-2) → S
B → (-2) → Z → (-2) → X → (-2) → V → (-2) → T
C→ (+2) → E → (+2) → G → (+2) → I → (+2) → K
D → (+2) → F → (+2) → H → (+2) → J → (+2) → L
So, the letter-cluster that replaces the (?) to complete the series is "STKL"