Find the odd 4-letter block (consistent +2 steps, then large negative): Select the item that does not share the “+2, +2, then big negative jump” structure.

Introduction / Context:
Many quartet patterns build momentum with two equal forward steps and then reset with a larger backward jump. Items that introduce wraparound irregularities break the shared rhythm and become the outlier.

Given Data / Assumptions:

• DFHB: D→F (+2), F→H (+2), H→B (large −6) → fits.
• KMOJ: K→M (+2), M→O (+2), O→J (−5) → broadly fits the “two +2 then back” structure.
• PRTN: P→R (+2), R→T (+2), T→N (−6) → fits.
• XZBV: X→Z (+2), Z→B (wrap irregular), B→V (+20) → breaks the clean “two +2 then back” cadence.

Concept / Approach:
We are judging structural similarity: two modest forward moves followed by a backward correction. The option that requires a wraparound forward leap at the end does not match.

Step-by-Step Solution:

Verification / Alternative check:
Visualizing positions on the alphabet line highlights XZBV’s end leap versus the others’ backward correction.

Why Other Options Are Wrong:
They share the structural rhythm (two +2 forward steps, then a retreat).

Common Pitfalls:
Do not focus on the exact magnitude of the backward step; the direction and structure are the key.

Final Answer:
XZBV