Based on the English alphabetical order, three of the following four letter-cluster pairsare alike in a certain way and thus form a group. Which letter-cluster pair DOES NOTbelong to that group?(Note: The odd one out is not based on the number of consonants/vowels or theirposition in the letter-cluster.)

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

Now, we check each options.

Option (a): FI - IJ (Not Follow)

F + 2 $$\neq$$​ I, I + 2 $$\neq$$​ J

Option (b): QV - SX (Follow)​

Q + 2 = S, V + 2 = X

Option (c): KP - MR (Follow)​

K + 2 = M, P + 2 = R

Option (d): NS - PU (Follow)​​

N + 2 = P, S + 2 = U

Thus, correct option is (a).