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

Logic: 1st letters + 2 = 2nd letters, 2nd letters + 5 = 3rd letters.

Option (a): DFO

D + 2 = F, F + 9 = O

Option (b): MOT

M + 2 = O, O + 5 = T

Option (c): SUZ

S + 2 = U, U + 5 = Z

Option (d): LNS

L + 2 = N, N + 5 = S

There are three options B, C, D which are following the same logic:.

So, the correct odd one out is DFO

Thus, the correct option is (a) DFO.