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 is the letter-cluster pair that 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.)​

​Logic: Both letters decrease by 5.

Option A: LK → KJ

L → K => –1

K → J => –1
Option B: HI → CD

H → C => –5

I → D => –5
Option C: QR → LM

Q → L => –5

R → M => –5

Option D: PQ → KL

P → K => –5

Odd One Out:

Only Option A has a different pattern (–1, –1), while all others have –5, –5.