Select the option that is related to the third letter-cluster in the same way as the second letter-cluster is related to the first letter-cluster. TV : MO :: GR : ?

AK ZL ZK AM

ZK

Pattern followed is : TV : MO T(20) - 7 = (13)M , V(22) - 7 = (15)O Similarly , GR : ? G(7) - 7 = (26)Z , R(18) - 7 = (11)K ZK , is correct answer .