Select the letter-clusters that can replace the question mark (?) in the following series.

FAN, JDP, NGR, ?, VMV

RJT

Explanation:

FAN, JDP, NGR, ?, VMV

The logic followed here is :

F → (-2) → J → (-2) → N → (-2) → R → (-2) → V

A → (-2) → D → (-2) → G → (-2) → J → (-2) → M

N → (+2) → P → (+2) → R → (+2) → T → (+2) → V

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