In the following letter analogy, MN changes to NM by reversing the order of letters. Using the same pattern, which pair of letters should complete the analogy MN : NM :: JK : ?

Introduction / Context:
This question is a simple letter analogy based on reversing the order of two letters. We are shown how MN becomes NM, and we must apply the same idea to JK. Letter reversal analogies like this test attention to the direction and sequence of symbols rather than any complex arithmetic pattern.

Given Data / Assumptions:
First pair: MN : NM. Second pair: JK : ?. Only the order of letters changes; the letters themselves are not replaced by others. The relationship must be identical in both pairs.

Concept / Approach:
In the pair MN : NM, the two letters are exactly the same but appear in reversed order in the second term. There is no shifting forward or backward in the alphabet; only the positions of the letters are swapped. Therefore, the pattern is simply reversal of the pair. To complete the analogy, we must reverse the pair JK in exactly the same way, creating a new pair with the letters in opposite order.

Step-by-Step Solution:
Step 1: Observe what happens from MN to NM. The first letter M becomes the second letter in the new pair. The second letter N becomes the first letter in the new pair. Thus MN is reversed to become NM. Step 2: Apply the same reversal to JK. Start with the pair JK. The first letter J should become the second letter in the new pair. The second letter K should become the first letter in the new pair. Therefore JK becomes KJ. Step 3: Match this result with the options. KJ appears among the options, so KJ is the correct completion of the analogy.

Verification / Alternative check:
We can restate the pattern in words: the second pair is obtained by writing the first pair backwards. This works exactly for MN and NM, and it also works for JK and KJ. Any option that does not simply reverse the original pair breaks this clear rule. Therefore choosing KJ preserves the relationship in a consistent and straightforward manner.

Why Other Options Are Wrong:
RS and SR use entirely different letters and are not simple reversals of JK. PQ and QP again use different letters and ignore the fact that the original pair JK must be preserved, only reversed.

Common Pitfalls:
Some students may be tempted by pairs such as PQ, QP, RS, or SR because they look similar to JK in being consecutive letters. However, the question is not asking for another pair of consecutive letters; it is asking for the same transformation pattern that changed MN into NM. When the transformation is a pure reversal, the safest strategy is to keep the same letters and simply swap their positions. Keeping this principle in mind helps avoid simple but common errors.

Final Answer:
Using the same reversal pattern, JK should change to KJ.