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

Logic: Each letter increased by +8 places in english alphabet.

Let's check the options:

Option (a): NVD
N + 8 = V
V + 8 = D

Option (b): ΙΟΥ  (Pattern not Follow)
I + 6 = O
O + 10 = Y

​Option (b): JRZ
J + 8 = R
R + 8 = Z 
​Option (d): PXF
P + 8 = X
X + 8 = F 

Odd one Out: Option (b) IOY does not follow the same logic as other options follow to making it odd one out.

Thus, the correct option is (b) IOY