Find the ODD one out from the given options.

Correct option is C

Option (a) BY:
B is the 2nd letter.
Its opposite in the alphabet is Y (25th letter).
Option (b) EV:
E is the 5th letter.
Its opposite in the alphabet is V (22nd letter).
Option (c) CW:
C is the 3rd letter.
The opposite of C should be X (24th letter), but here it is W.
Option (d) AZ:
A is the 1st letter.
Its opposite in the alphabet is Z (26th letter).
All the pairs represent opposite letters in the alphabet except "CW", where the opposite of C should be X, not W. Hence, CW is the odd one out.
Correct answer: (c) CW.