Select the option that will fill in the blank and complete the given series. FTB, IQE, LNH, OKK, ?

SHN RHN SHM RGM

RHN

Explanation: FTB, IQE, LNH, OKK, ? The logic followed here is : F → (+3) → I → (+3) → L → (+3) → O → (+3) → R T → (-3) → Q → (-3) → N → (-3) → K → (-3) → H  B → (+3) → E → (+3) → H → (+3) → K → (+3) → N   So, the letter-cluster that replaces the (?) to complete the series is "RHN'