Four letter clusters have been given, out of which three are alike in some manner and one is different. Select the letter cluster that is different. (NOTE: The odd one out is not based on the number of consonants/vowels or their position in the letter cluster.)

Correct option is A

Concept:
All except option (a) follow the same pattern.
Explanation:
CWSR → C – 6 = W; W – 4 = S; S – 1 = R
MGCA → M – 6 = G; G – 4 = C; C – 2 = A
KEAY → K – 6 = E; E – 4 = A; A – 2 = Y
SMIG → S – 6 = M; M – 4 = I; I – 2 = G
From the analysis, we can see:
In options, (b), (c), and (d), the letters in the letters cluster follow the same pattern.
In option (a), the letters in the letter cluster do not follow the same pattern.
Therefore, the odd option is (a), CWSR.