A close up of a keyboard Description automatically generated
According to the positional values of the alphabets,
1) AZ126 → A = 1, Z = 26 → 126
2) BU221 → B = 2, U = 21 → 221
3) EW523 → E = 5, W = 23 → 523
4) CY324 → C = 3, Y = 25 → 325 and not 324
Hence, the odd one among the given options is CY324.