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

FCC, UFH, OIS, LLX, FOC, ?

URH

Explanation:

FCC, UFH, OIS, LLX, FOC, ?

The logic followed here is :

F → (-11) → U → (-6) → O → (-3) → L → (-6) → F → (-11) → U

C → (+3) → F → (+3) → I → (+3) → L → (+3) → O → (+3) → R

C → (+5) → H → (+11) → S → (+5) → X → (+5) → C → (+5) → H

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