In this letter analogy question, select the group of letters that completes the pattern: ZXVT : YWUS :: RPNL : ?

Introduction / Context:
Letter based analogies often involve shifting each letter by a fixed number of positions in the alphabet. In this question the pair ZXVT and YWUS is given and you must apply the same pattern to RPNL to find the missing group of letters. These problems check your comfort with alphabet positions and consistent transformations across multiple letters.

Given Data / Assumptions:
- The first pair is ZXVT and YWUS, each with four letters.
- The second group RPNL also has four letters and must be transformed using the same rule that connects ZXVT to YWUS.
- The alphabet positions follow A=1, B=2, up to Z=26.
- The options provided are XVTS, TSQP, SQPM, and QOMK.

Concept / Approach:
The idea is to look at how each letter in the first group changes to produce the second group. If the change is consistent, such as moving one position backward or forward, that transformation can be generalized. After you identify the rule between ZXVT and YWUS, you apply it letter by letter to RPNL and then match the result with one of the answer choices. Thinking in terms of positions rather than just letter shapes makes this process systematic and reliable.

Step-by-Step Solution:
Step 1: Convert ZXVT to numeric positions: Z=26, X=24, V=22, T=20.Step 2: Convert YWUS to numeric positions: Y=25, W=23, U=21, S=19.Step 3: Compare each pair: 26 to 25, 24 to 23, 22 to 21, and 20 to 19. Each letter decreases by 1 position in the alphabet.Step 4: Now apply the same shift of minus 1 to RPNL. The positions are R=18, P=16, N=14, L=12.Step 5: Subtract 1 from each: R (18) goes to Q (17), P (16) goes to O (15), N (14) goes to M (13), and L (12) goes to K (11).Step 6: The resulting letters form QOMK, which matches option D, so QOMK is the correct completion.

Verification / Alternative check:
As a quick verification, you can reverse the transformation for the chosen answer. Starting from QOMK and adding 1 to each letter position gives RPNL, which is the original second group. This confirms that the mapping is consistent and reversible. Testing other options in the same way shows that they do not correspond to a simple minus one shift from RPNL, so they cannot be correct under the established rule.

Why Other Options Are Wrong:
- XVTS: This group does not arise from subtracting 1 from the letters of RPNL and therefore breaks the observed pattern.
- TSQP: The order and letter positions do not match a uniform shift of minus 1 from RPNL, so it is inconsistent with the first pair.
- SQPM: Although some letters look similar, the sequence is wrong and does not follow the simple backward shift that maps ZXVT to YWUS.

Common Pitfalls:
A common error is to focus on the internal pattern within each group, such as the apparent symmetry, instead of checking how the first group maps to the second. Another pitfall is to miscount alphabet positions or shift in the wrong direction. To avoid mistakes, always convert letters into numbers, write down the change clearly, and then apply it accurately to the new group. A small amount of organized work greatly reduces confusion in letter analogy questions.

Final Answer:
Because each letter in ZXVT moves one step backward in the alphabet to produce YWUS, the same minus one rule applied to RPNL gives QOMK. Therefore the correct answer is QOMK.