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 - 3 = 2nd letters, 2nd letters + 4 = 3rd letters.

Option (a):  LIM

L - 3 = I, I + 4 = M

Option (b):  BYC

B - 3 = Y, Y + 4 = C

Option (c):  QNR

Q - 3 = N, N + 4 = R

Option (d):  IGJ

I - 2 = G, G + 3 = J

There are only three options A, B, C which are following the same logic: 

So, the correct odd one out is IGJ.​

Thus, the correct option is (d) IGJ.