A backout plan provides a documented procedure to revert or undo a change if it fails or causes issues, helping to restore the environment quickly and prevent extended downtime. Having a backout plan in place minimizes impact during failed changes. User notification (A) informs users but does not prevent failures. Change approval (B) and risk analysis (C) occur before the change and cannot fix issues after failure. Backout planning is a best practice in Change Management covered in Security Program Management#6: Chapter 16 CompTIA Security+ Study Guide#