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

a) OQS- O+2=Q+2=S 

b) JLN - J+2=L+2 =N

c) UWY- U+2=W+2=Y

d) ADG- A+3=D+3=G

A, B, and C follow the pattern of +2 increments between consecutive letters.

​D follows a different pattern of +3 increments between consecutive letters.

​ADG is the odd one out.

Thus, correct answer is (d) ADG