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

TSF, RPJ, PMN, NJR, ? 

LGV 

Explanation:

TSF, RPJ, PMN, NJR, ? 

The logic followed here is :

T → (-2) → R → (-2) → P → (-2) → N → (-2) → L

S → (-3) → P → (-3) → M → (-3) → J → (-3) → G

F → (+4) → J → (+4) → N → (+4) → R → (+4) → V

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