Find the odd one out.

The correct answer is SRQ.

To find the odd one out, let us analyze the alphabetical order and relationship of the letters in each option:
1. CDE: The letters are in continuous alphabetical order: C (3rd letter) → D (4th letter) → E (5th letter).
2. KLM: The letters are in continuous alphabetical order: K (11th letter) → L (12th letter) → M (13th letter).
3. TUV: The letters are in continuous alphabetical order: T (20th letter) → U (21st letter) → V (22nd letter).
4. SRQ: The letters are in reverse alphabetical order: S (19th letter) → R (18th letter) → Q (17th letter).

Since "SRQ" is the only group of letters that is written in reverse alphabetical order while all the other options are written in normal forward alphabetical order, it is the odd one out.