What is the purpose of code refactoring?

The correct choice highlights that the primary aim of code refactoring is to restructure existing code while maintaining its external behavior. Refactoring involves making changes to the internal workings of a codebase, enhancing its readability, reducing complexity, and improving maintainability without altering how the software behaves from the user's perspective.

This practice is essential in software development, as over time, code can become convoluted or difficult to work with due to additions, modifications, or quick fixes that may have been implemented during development. By refactoring, developers can improve the organization and clarity of the code, making it easier for themselves and others to understand, extend, and modify in the future.

While the other options mention important aspects of coding and maintenance, they do not encapsulate the essence of refactoring as clearly as the chosen answer. Changing the external behavior might indicate a different process, such as feature enhancement or bug fixing, instead of focusing on internal organization. Adding new features and deleting code can be part of the development lifecycle but are not the core objectives of refactoring.