Using each letter exactly once, how many meaningful English words can be made from the letters E, P, R, O?

Introduction / Context:
We must count standard English words (no abbreviations) that can be formed using all letters E, P, R, O exactly once each.

Given Data / Assumptions:

• Letters: E, P, R, O.
• Every valid word must be 4 letters long and use each letter once.
• Exclude abbreviations like “repo” (database jargon) if not treated as standard lexical entries in such tests.

Concept / Approach:
Enumerate common anagrams and filter to standard words.

Step-by-Step Solution:

Verification / Alternative check:
Cross-check both “ROPE” and “PORE” as widely accepted in basic vocabulary lists; others are either misspellings or abbreviations.

Why Other Options Are Wrong:

• None/One: Under-counts; there are at least two.
• Three: Over-counts by including an abbreviation or non-word.

Common Pitfalls:
Counting “REPO” as a dictionary headword rather than an abbreviation in reasoning test norms.

Final Answer:
Two