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

GAVE: AGEV :: KEPT : EKTP :: ACID : ?

CADI

A   B   C    D   E    F   G    H    I    J    K    L   M

 ↓    ↓    ↓    ↓    ↓     ↓   ↓    ↓     ↓   ↓    ↓    ↓    ↓

 Z   Y    X   W   V    U   T    S    R   Q   P    O   N

26  25  24  23  22  21  20  19  18  17  16  15  14

******************************************

GAVE: AGEV :: KEPT : EKTP :: ACID : ?

The  logic followed here is :

FIRST AND SECOND INTERCHANGED WITH EACH OTHER

THIRD AND FOURTH INTERCHANGED WITH EACH OTHER

AS

G → (INTERCHANGED WITH SECOND )→ A

A → (INTERCHANGED WITH FIRST ) → G

V → (INTERCHANGED WITH FOURTH )→ E

E → (INTERCHANGED WITH THIRD )→ V

AND

K → (INTERCHANGED WITH SECOND )→ E

E → (INTERCHANGED WITH FIRST ) → K

P → (INTERCHANGED WITH FOURTH )→ T

T → (INTERCHANGED WITH THIRD )→ P

SIMILARLY

A → (INTERCHANGED WITH SECOND )→ C

C → (INTERCHANGED WITH FIRST ) → A

I → (INTERCHANGED WITH FOURTH )→ D

D → (INTERCHANGED WITH THIRD )→ I