In this letter series question, select the odd group of letters from the given alternatives based on the pattern formed by pairs of letters.

Introduction / Context:
This is a letter pattern reasoning question where each option is a group of four letters. The task is to identify the group that does not follow the same alphabetic rule as the others. Such problems are common in non verbal reasoning sections and strengthen a candidate's ability to observe structured patterns in sequences.

Given Data / Assumptions:
- The letter groups are IMOR, ORIL, UXCF, and ADWZ.- Letters are taken from the English alphabet and appear in pairs inside each group.- The pattern is likely based on fixed jumps between specific pairs of letters.

Concept / Approach:
A helpful approach is to look at each four letter group as two distinct pairs: first two letters and last two letters. Then we can check the difference in alphabetical positions within each pair. If three groups show the same constant difference in both pairs and one does not, the non matching group is the odd one out.

Step-by-Step Solution:
Step 1: For ORIL, consider pairs (O, R) and (I, L). O is the 15th letter, R is 18th, so the difference is plus 3. I is the 9th letter, L is 12th, again a difference of plus 3.Step 2: For UXCF, consider pairs (U, X) and (C, F). U is 21st and X is 24th, difference plus 3. C is 3rd and F is 6th, also difference plus 3.Step 3: For ADWZ, consider pairs (A, D) and (W, Z). A is 1st and D is 4th, difference plus 3. W is 23rd and Z is 26th, again plus 3.Step 4: For IMOR, consider pairs (I, M) and (O, R). I is 9th and M is 13th, difference plus 4. O is 15th and R is 18th, difference plus 3. The two pairs do not share the same step size.Step 5: Therefore, three groups maintain a consistent gap of plus 3 in both pairs, while one group has mismatched gaps.

Verification / Alternative check:
You can quickly note that ORIL, UXCF, and ADWZ are formed by taking one letter and then jumping exactly three places ahead to get the next in each pair. IMOR breaks this rule with a jump of four followed by a jump of three.

Why Other Options Are Wrong:
ORIL: Both pairs increase by three positions.UXCF: Again increases by three in each pair.ADWZ: Follows the same plus three rule for both pairs.

Common Pitfalls:
Some candidates try to see a single continuous pattern across all four letters instead of separating them into pairs. For this question, treating each pair independently makes the hidden structure much clearer.

Final Answer:
The odd letter group is IMOR because it does not maintain the same alphabetical step size in both of its pairs, unlike the other groups.