Select the option that is related to the fifth alphanumeric-cluster in the same way as the second alphanumeric-cluster is related to the first alphanumeric-cluster and the fourth alphanumeric-cluster is related to the third alphanumeric-cluster.

P4 : N9 :: M16 : K25 :: G49 : ?

E64

Pattern followed is :

P4 : N9

P(16) - 2 = (14)N  &  Adjacent terms are in this pattern  2²   :    (2+1)²

M16 : K25

M(13) - 2 = (11)K , Adjacent terms are in this pattern 4²   :    (4+1)²

Similarly ,

G49 : ?

G(7) - 2 = (5)E  &  Adjacent terms are in this pattern  7²   :    (7+1)²

Hence , E64 is correct answer .