Find the odd letter triple (step pattern +2 then +4): Choose the option that does not follow the increases of +2 then +4 in alphabet order.

Introduction / Context:
Many alphabet puzzles rely on fixed jumps between letters. A common construct is a two-step pattern such as “+2, then +4”. Detecting the arithmetic on positions (A=1, …, Z=26) reveals the consistent rule quickly.

Given Data / Assumptions:

• H → J (+2), J → N (+4) → HJN fits.
• J → L (+2), L → P (+4) → JLP fits.
• Q → S (+2), S → W (+4) → QSW fits.
• P → R (+2), R → U (+3) → PRU does not fit (+2, +3 instead of +2, +4).

Concept / Approach:
Translate each letter to its index and verify successive differences. The single item that breaks the “+2 then +4” structure is the odd one out.

Step-by-Step Solution:

Verification / Alternative check:
Reversing the test (checking -2, -4 from right to left) produces the same conclusion for the three conforming cases and still flags PRU as inconsistent.

Why Other Options Are Wrong:
They faithfully implement the +2, then +4 rule.

Common Pitfalls:
Do not wrap across Z here; none of the conforming items require wrap-around, which keeps the pattern transparent.

Final Answer:
PRU