Which of the following letter-clusters will replace the question mark (?) in the given series ?

RLV, PNS, NPP, ? , JTJ

LRM

Explanation:

RLV, PNS, NPP, ? , JTJ

The logic followed here is :

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

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

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

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