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 D

Option (A) ZZ → XD

Z (26) → X (24): –2
Z (26) → D (4): +4
Pattern: first letter - 2 = third letter and second letter + 4 = fourth letter
Option (B) VH → TL
V (22) → T (20): –2
H (8) → L (12): +4
Option (C) DR → BV
D (4) → B (2): –2
R (18) → V (22): +4
Option (D) AC → DF
A (1) → D (4): +3
C (3) → F (6): +3
Logic Observed:
Conclusion:
Only Option (D) breaks the common transformation pattern seen in the other three.