Based on the English alphabetical order, three of the following four letter-cluster pairs are alike in a certain way and thus form a group. Which letter-cluster pair DOES NOT belong to that group?
(Note: The odd one out is not based on the number of consonants/vowels or their position in the letter-cluster.)

Correct option is A

Check each options:
Logic:
1st letter − 5 = 3rd letter
2nd letter − 6 = 4th letter

​Option (A): GK – BF
G − 5 = B 
K − 6 = E  (but 4th letter is F) → does not follow the logic
Option (B): SW – NQ
S − 5 = N 
W − 6 = Q  → follows the logic
Option (C): UY – PS
U − 5 = P 
Y − 6 = S  → follows the logic
Option (D): LP – GJ
L − 5 = G 
P − 6 = J → follows the logic
Thus, the letter-cluster pair that does NOT belong to the group is (A).