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

CLAY, DIFX, EFKW, FCPV, ?

GZUU

Explanation:

CLAY, DIFX, EFKW, FCPV, ?

The logic followed here is :

C → (+1) → D → (+1) → E → (+1) → F → (+1) → G

L → (-3) → I → (-3) → F → (-3) → C → (-3) → Z

A → (+5) → F → (+5) → K → (+5) → P → (+5) → U

Y → (-1) → X → (-1) → W → (-1) → V → (-1) → U

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