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.)​

Logic: 1st letter + 8 = 3rd letter and 2nd letter + 4 = 4th letter

Now, we check each options.

Option (a):​ XV – FZ (Follow)

X + 8 = F, V + 4 = Z

Option (b): BZ – JD (Follow)​

B + 8 = J, Z + 4 = D

Option (c): HF – PJ (Follow)​

H + 8 = P, F + 4 = J

Option (d): YX – GA (Not Follow)​

Y + 8 = G, X + 4 $$\neq$$​ A

Thus, correct option is (d).