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

A + 4 = E

A + 2 = C

C + 5 = H

C + 2 = E (Not Follow)

L + 4 = P

L + 2 = N

T + 4 = X

T + 2 = V

So, the Odd one out is: (b)

Thus, the correct option is: (b)