Four letter-clusters have been given, out of which three are alike in some manner and one is different. Select the letter-cluster that is different.

HJRQ

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;

(Last 2 letters are opposite of 1st two letters)

1) HJRQ,

H → OPPOSITE → S not R

J → OPPOSITE → Q

H → (+2) → J

2) ACZX,

A → (+2) → C

A → OPPOSITE → Z

C → OPPOSITE → X

3) KMPN,

K → (+2) → M

M → OPPOSITE → N

P → OPPOSITE → K

Thus, HJRQ is the odd one.