Four letter-clusters have been given, out of which three are alike in some manner and one is different. Select the odd letter-cluster.

SQOMK

THE LOGIC;

1) KMOQS,

K → (+2) → M → (+2) → O → (+2) → Q → (+2) → S

2) SQOMK,

S → (-2) → Q → (+2) → O → (+2) → M → (+2) → K

3) FHJLN,

F → (+2) → H → (+2) → J → (+2) → L → (+2) → N

4) PRTVX,

P → (+2) → R → (+2) → T → (+2) → V → (+2) → X

Thus, SQOMK is the odd one.