Select the letter cluster that can replace the question mark (?) in the following series.
RAP, SCS, TEV, UGY, ?
Answer & explanation
Correct answer: option 3

Explanation:
RAP, SCS, TEV, UGY, ?
The logic followed here is :
R → (+1) → S → (+1) → T → (+1) → U → (+1) → V
A → (+2) → C → (+2) → E → (+2) → G → (+2) → I
P → (+3) → S → (+3) → V → (+3) → Y → (+53 → B
So, the letter-cluster that replaces the (?) to complete the series is "VIB"