In the following letter pair analogy, MOK is related to KLG. Using the same alphabetic shift pattern, which of the following pairs correctly completes the analogy?

Introduction / Context:
This analogy involves three letter groups and checks the ability to recognise different alphabetic shifts applied to each position. The reference pair MOK : KLG suggests that each letter has been shifted by a different fixed amount. The challenge is to identify these shifts and then choose the option where the first group of three letters changes to the second group using the same pattern. Recognition of positional shifts is a common requirement in letter based logical reasoning questions.

Given Data / Assumptions:
- The first pair given is MOK and KLG.
- The letters are all capital, and we use the English alphabet positions A = 1 to Z = 26.
- Each letter in MOK may be shifted by a different constant to obtain KLG.
- The correct option must apply the same set of shifts to its own first triple to produce its second triple.

Concept / Approach:
First, convert each letter into its numeric position. M is 13, O is 15, K is 11. K is 11, L is 12, G is 7. The shift from M to K is minus 2, from O to L is minus 3, and from K to G is minus 4. Thus the pattern is position one minus two, position two minus three, and position three minus four. We now test each option to see which first triple transforms into the second triple under this exact sequence of shifts. Only the pair that follows minus two, minus three, and minus four consistently is acceptable.

Step-by-Step Solution:
Step 1: Compute the shifts for MOK to KLG. M(13) to K(11) is minus two. Step 2: O(15) to L(12) is minus three. Step 3: K(11) to G(7) is minus four. Step 4: Apply the same pattern to option A, FIM : DFI. F(6) minus two equals D(4), I(9) minus three equals F(6), and M(13) minus four equals I(9). Step 5: All three letters in FIM transform perfectly into DFI under the pattern minus two, minus three, minus four. Step 6: Test the other options quickly and see that they do not follow this exact sequence of decreases, so option A uniquely matches the original rule.

Verification / Alternative check:
We can reconfirm by reversing the operation for option A. Adding two, three, and four to DFI should bring us back to FIM. D(4) plus two gives F(6), F(6) plus three gives I(9), and I(9) plus four gives M(13), demonstrating that the transformation is symmetric and stable. The original pair MOK and KLG also shows this behaviour, so the pattern is confirmed. Other options either use different shifts, unequal shifts, or include letters that would fall outside the alphabet if the same subtraction were applied.

Why Other Options Are Wrong:
Option B, TMA : UNB, involves different directional shifts and does not match the minus two, minus three, minus four pattern. Option C, KCN : JBM, and option D, FSA : IVD, also fail when checked position by position, because their letters do not reduce by the same set of values. Without a consistent transformation, they cannot represent the same relationship as MOK : KLG.

Common Pitfalls:
A typical mistake is to assume that every letter shifts by the same amount, leading to rejection of the correct pattern. Another pitfall is miscounting alphabet positions or forgetting that separate positions can have separate fixed shifts. To avoid errors, always record the numeric positions of the letters and calculate the differences carefully for each position. Then apply the exact same sequence of changes to each candidate pair to see which one matches the model pattern exactly.

Final Answer:
The only pair that follows the position wise shifts minus two, minus three, and minus four, just as MOK changes to KLG, is FIM : DFI, so option A is correct.