Select the letter-cluster from among the given options that can replace the question mark (?) in the following series.
DOWN, CRRU, BUMB, AXHI, ?
Answer & explanation
Correct answer: option 4

Explanation:
DOWN, CRRU, BUMB, AXHI, ?
The logic followed here is :
D → (-1) → C → (-1) → B → (-1) → A → (-1) → Z
O → (+3) → R → (+3) → U → (+3) → X → (+3) → A
W → (-5) → R → (-5) → M → (-5) → H → (-5) → C
N → (+7) → U → (+7) → B → (+7) → I → (+7) → P
So, the letter-cluster that replaces the (?) to complete the series is "ZACP"