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 one out is not based on the number of consonants/vowels or their position in the letter cluster.)

From the given options - 

(A) VWZU
V → W (+1)
W → Z (+3)
Z → U (-5)
(B) EFHD
E → F (+1)
F → H (+2)
H → D (-4)
(C) MNQL
M → N (+1)
N → Q (+3)
Q → L (-5)
(D) OPSN
O → P (+1)
P → S (+3)
S → N (-5)
VWZU, MNQL, and OPSN follow the pattern (+1, +3, -5).
EFHD follows (+1, +2, -4), which is different.
Thus, EFHD does not follow the same pattern as the others.

Therefore, the correct answer is (b). ​​