In this letter analogy, ACEG is related to BDFH. Using the same pattern, which group of letters should complete the analogy ACEG : BDFH :: IKMO : ?

Introduction / Context:
This problem is a letter series analogy that focuses on positional shifts in the alphabet. The given pair ACEG : BDFH shows a clear pattern where each corresponding letter in the second group is obtained by a simple shift from the first group. The task is to identify that pattern and then apply it to IKMO to find the correct related group.

Given Data / Assumptions:
First pair: ACEG : BDFH. Second pair: IKMO : ?. All letters are standard English capital letters. The same transformation is applied position wise.

Concept / Approach:
For such letter analogy questions, converting letters to their alphabet positions is very helpful. The main idea is to look for a constant positional change from each letter in the first group to the corresponding letter in the second group. Once the rule is found, the same change is applied to the letters of IKMO to generate the missing term. The pattern in this question uses a simple plus one shift for each position.

Step-by-Step Solution:
Step 1: Convert ACEG to positions. A = 1, C = 3, E = 5, G = 7. Step 2: Convert BDFH to positions. B = 2, D = 4, F = 6, H = 8. Step 3: Compare position wise. 1 to 2 is +1, 3 to 4 is +1, 5 to 6 is +1, 7 to 8 is +1. So each letter in ACEG is moved one step forward in the alphabet to produce BDFH. Step 4: Apply the same +1 rule to IKMO. I = 9, K = 11, M = 13, O = 15. 9 + 1 = 10, which is J. 11 + 1 = 12, which is L. 13 + 1 = 14, which is N. 15 + 1 = 16, which is P. So IKMO becomes JLNP.

Verification / Alternative check:
To verify, apply the reverse operation to JLNP. J back by one is I, L back by one is K, N back by one is M, and P back by one is O, which restores the original group IKMO. This mirrors exactly how ACEG transforms to BDFH and confirms that the pattern is a consistent plus one shift for each letter. No other option matches this exact transformation rule.

Why Other Options Are Wrong:
IJKL does not arise from a constant shift of plus one from IKMO. It introduces letters not aligned with the positional rule. KLMN represents a sequence of consecutive letters starting from K and ignores the structure of IKMO. HIJK shifts some letters backward and does not correspond to the plus one pattern. JMOP partly resembles the starting letter J but breaks the consistent pattern for the remaining positions and cannot be obtained by adding one to each letter of IKMO.

Common Pitfalls:
Learners sometimes focus only on obvious sequences like ABCD or KLMN and overlook the fact that analogy questions demand a consistent transformation between corresponding letters, not just any familiar sequence. Another frequent mistake is to check the pattern for only the first two letters and then guess. In examinations, it is crucial to test the rule on all positions in both pairs to ensure accuracy. Consistency across every letter is the key to solving such questions reliably.

Final Answer:
The letter group that completes the analogy is JLNP.