Which of the following is the BEST method to maintain an audit trail of changes made to the source code of a program?

Standardized file naming conventions improve organization but do not provide an audit trail of changes *within* the files themselves.

Automated version control systems (VCS) like Git or SVN are specifically designed to track every change made to source code, including the author, timestamp, and a commit message explaining the change. This provides a comprehensive, immutable, and easily queryable audit trail essential for collaboration, rollback, and compliance.

Embedding details within source code (e.g., comments) is manual, prone to error and omission, and difficult to search or enforce consistently for an audit trail.

Documenting details on a change register is a manual process separate from the code itself, making it susceptible to discrepancies and not directly linked to the actual code changes, unlike an automated VCS.