What is refactoring?

• A. Improved design, code base without changing external system behavior
• B. Adding new features with external API changes
• C. Rewriting code in a different language
• D. Removing tests

Answer: (A)

Refactoring means reorganizing and cleaning up the internal structure of existing code to improve design, readability, and maintainability without changing how the system behaves from an external perspective. It focuses on reducing complexity, removing duplication, and clarifying abstractions while keeping the same features and outputs. This practice helps keep the codebase healthier so future changes are easier and safer.

This item matches because it describes improving the design and the codebase without altering external behavior. The other options involve adding features with API changes, rewriting in a different language, or removing tests—activities that change functionality, interfaces, or verification, none of which are refactoring.