Select the odd group of letters from the given alternatives: XVT, NPR, LJH, and FDB.

Introduction / Context:
This question examines your skill in identifying patterns in letter sequences. Each option is a group of three letters, and you must find the group that does not follow the same alphabetical movement as the others. Problems of this type test your understanding of ascending and descending sequences in the English alphabet.

Given Data / Assumptions:

• The four groups are XVT, NPR, LJH, and FDB.
• Each group contains three letters, arranged in a particular order.
• Three of the groups move backward in the alphabet, while one group moves forward.
• We assume standard positions in the alphabet where A = 1, B = 2, ..., Z = 26.

Concept / Approach:
The core idea is to check whether letters in each group are moving forwards or backwards through the alphabet and to observe the size of the step between consecutive letters. In this problem, three of the groups follow a decreasing pattern with a fixed negative step, while one of the groups follows an increasing pattern with a positive step. The sequence that differs in direction is the odd one out.

Step-by-Step Solution:
Step 1: For XVT, positions are X = 24, V = 22, T = 20. Differences are 22 - 24 = -2 and 20 - 22 = -2, so the pattern is -2, -2. Step 2: For NPR, positions are N = 14, P = 16, R = 18. Differences are 16 - 14 = +2 and 18 - 16 = +2, so the pattern is +2, +2. Step 3: For LJH, positions are L = 12, J = 10, H = 8. Differences are 10 - 12 = -2 and 8 - 10 = -2, giving a -2, -2 pattern. Step 4: For FDB, positions are F = 6, D = 4, B = 2. Differences are 4 - 6 = -2 and 2 - 4 = -2, again -2, -2. Step 5: Compare the directions. XVT, LJH, and FDB all move backwards through the alphabet with steps of minus 2. Step 6: NPR is the only group where the letters move forward with a step of plus 2. Step 7: Therefore, NPR is the odd group of letters among the four alternatives.

Verification / Alternative check:
You can verify this visually by reciting the alphabet. X, V, T involves moving backwards two letters each time. L, J, H and F, D, B show the same backward movement. In contrast, N, P, R involves moving forward two letters each time. Since three of the sets are clearly descending sequences and only one is ascending, NPR stands out as the odd one. This mental check agrees with the numerical position method.

Why Other Options Are Wrong:
XVT is a descending sequence with step size minus 2 and matches LJH and FDB, so it is not the odd one out.
LJH also shows a backward movement in the alphabet with the same step and belongs with XVT and FDB.

FDB follows the same decreasing pattern and clearly belongs to the main group, so it cannot be the different option.

Common Pitfalls:
A common mistake is to check only that letters are adjacent or spaced, without paying attention to whether the sequence moves forward or backward. Since all four groups show equal steps, it is easy to miss the direction difference. Another pitfall is miscounting positions, particularly near the extremes of the alphabet. To avoid these issues, always compute differences in a consistent order and note whether you are moving up or down in letter positions. Practising a few such questions will make this process more automatic and reliable.

Final Answer:
The odd group of letters is NPR.