Explanation:

Let’s break down each option and see what’s really going on:

- JPN, MSQ, and QWU: In all these clusters, the positions of each letter in the alphabet increase by +3 for each subsequent letter. For example:

- J (10) ? P (16) is +6, but if you look closely: J?P (skip three letters: K,L,M,N,O), but the sequence is not holding consistently at +3, let's double-check.

- Actually, if you take J (10), P (16), N (14): The jump is +6 and then -2.

- MSQ: M (13), S (19), Q (17): +6, -2.

- QWU: Q (17), W (23), U (21): +6, -2.

So there is a pattern: the first to the second is +6, second to third is -2.

- Now look at CJI:

- C (3), J (10), I (9): First jump is +7, second is -1.

- This doesn't follow the +6, -2 pattern of the others.

- Basically, JPN, MSQ, QWU all follow: first letter +6, then -2. CJI is off the pattern.

So the odd one out is: Option 3 – CJI.

Option 3 is the correct answer.