A series of letter pairs is given with one pair missing. Select the pair that correctly continues the pattern: AZ, BY, CX, ?

Introduction / Context:
This is a classic alphabet series problem based on symmetric movement from the two ends of the alphabet. The first letters move forward from A, while the second letters move backward from Z. Your task is to find the next pair that preserves this symmetry.

Given Data / Assumptions:

• Given pairs: AZ, BY, CX, ? • The first letter of each pair progresses through the alphabet. • The second letter of each pair regresses through the alphabet. • Standard positions A = 1, Z = 26 are used.

Concept / Approach:
We observe that in each pair, the first letter starts near the beginning of the alphabet and moves forward, while the second letter starts near the end and moves backward. This is a common mirror style pattern in letter pair questions. Once we identify the next first letter and the next second letter, the pair is determined uniquely.

Step-by-Step Solution:
Step 1: List first letters in order. First letters: A, B, C, ? They increase by one position: A → B → C → D. So the next first letter must be D. Step 2: List second letters in order. Second letters: Z, Y, X, ? They decrease by one position: Z → Y → X → W. So the next second letter must be W. Step 3: Combine the letters to get the pair DW.

Verification / Alternative check:
Check the symmetry: A with Z are at the extremes of the alphabet, B with Y are next inwards, C with X are further inwards, and D with W continues this inward motion. No other option maintains this exact forward and backward single step progression from both ends simultaneously.

Why Other Options Are Wrong:
• WD: This reverses the correct order. The pattern clearly uses the ascending letter first and descending letter second. • DE: This pair has both letters advancing from the beginning side, breaking the mirror structure. • DX: The first letter D is correct but the second letter X does not continue the backward sequence from X to W.

Common Pitfalls:
Many candidates may choose WD because it uses the correct letters but in reversed order. Another pitfall is ignoring that the second letter is moving backward, not forward. Always track each position separately to avoid such traps.

Final Answer:
The pair that correctly completes the pattern is DW.