Based on the position in the English alphabetical order, three of the following letter- clusters are alike in some manner and one is different. Select the odd letter-cluster.

SPVT

1   2    3    4   5    6   7     8    9  10  11  12  13

 A   B   C    D   E    F   G    H    I    J    K    L   M

 ↓    ↓    ↓    ↓    ↓     ↓   ↓    ↓     ↓   ↓    ↓    ↓    ↓

 Z   Y    X   W   V    U   T    S    R   Q   P    O   N

26  25  24  23  22  21  20  19  18  17  16  15  14

THE LOGIC FOLLOWED HERE IS;

1) IGMJ,

I → (-2) → G

M → (-3) → J

2) SPVT,

S → (-3) → P

V → (-2) → T

3) DBHE,

D → (-2) → B

H → (-3) → E

4) NLRO,

N → (-2) → L

R → (-3) → O

Thus, SPVT does not belong to that group.