Select the letter-cluster from among the given options that can replace the question mark (?) in the following series.

MEND, PHJZ, SKFV, VNBR, ?

YQXN

Explanation:

Explanation:

MEND, PHJZ, SKFV, VNBR, ?

The logic followed here is :

M → (+3) → P → (+3) → S → (+3) → V → (+3) → Y

E → (+3) → H → (+3) → K → (+3) → N → (+3) → Q 

N → (-4) → J → (-4) → F → (-4) → B → (-4) → X

D → (-4) → Z → (-4) → V → (-4) → R → (-4) → N

So, the letter-cluster that replaces the (?) to complete the series is "YQXN"