In this letter analogy question, BCD is related to DEG, so you must select the set of letters that stands in the same relation to FIJ from the given alternatives.

Introduction / Context:

This is a three-letter analogy that requires careful observation of how each letter in one group is transformed to produce the corresponding letter in the next group. The pair "BCD : DEG" suggests a pattern of forward shifts in the alphabet, but not all shifts are identical. Your task is to detect the structure of these shifts and then apply a similar pattern to "FIJ" to find the correct related group from the options.

Given Data / Assumptions:

- First pair: BCD becomes DEG.
- Second pair to complete: FIJ becomes ?.
- Alphabet positions: A = 1, B = 2, ..., Z = 26.
- Options: HKN, JLN, FGH, KLN and HKM.
- The pattern relies on differences in positions of corresponding letters.

Concept / Approach:

The method is to convert letters into their numeric positions and examine the increments for each position from the first group to the second group. In "BCD : DEG", the shifts are not all equal, but they follow a particular numeric pattern. We then compute the shifts from FIJ to each option and look for the one that reflects a similar structure of increasing steps, especially in terms of relative differences between smallest and largest shifts.

Step-by-Step Solution:

Verification / Alternative check:

We can verify by explicitly checking other options. For HKN, the shifts from FIJ would be +2, +2 and +4, which gives a difference of 2 between smallest and largest shift. For FGH, the shifts include zero or negative movements. For KLN, the shifts are +5, +3 and +4, giving a range of 2. Only JLN has shifts of +4, +3 and +4, where the difference between the largest and smallest shift is 1, paralleling the pattern +2, +2 and +3 seen in the original pair. This structural similarity confirms that JLN is the correct completion.

Why Other Options Are Wrong:

HKN has shifts that jump from +2 to +4, giving a wider spread than in the original example and breaking the delicate pattern of near-equal increments.

FGH does not represent a consistent forward movement from FIJ and introduces smaller or negative changes, unlike the strictly forward shifts in BCD to DEG.

KLN uses shifts that vary too widely (+5, +3, +4) and does not match the small range of step sizes seen in the original pair.

HKM, though not one of the original options, similarly would not preserve the compact incremental structure if considered.

Common Pitfalls:

Many students try to find a single fixed shift for all letters, which does not exist in this question. Others may focus only on approximate numerical similarities without checking relative differences between the smallest and largest shifts. In multi-letter analogies, it is important to pay attention not only to the absolute values of the shifts but also to the overall pattern formed by those shifts.

Final Answer:

The letter group that most closely mirrors the pattern of shifts in the original pair is JLN.