A rollback plan, also known as a backout plan, is a strategy designed to reverse changes made during a project in case of failure or undesired results1. A rollback plan is a form of risk response that allows the project to restore the previous state and minimize the impact of the issue. A rollback plan is usually created during the planning phase and implemented during the execution or closing phase of the project. The other options are not correct because:

A compliance check is a process that ensures that the project meets the relevant standards, regulations, and requirements. A compliance check is not a risk response, but rather a quality control or assurance activity.

A release plan is a document that outlines the scope, schedule, and resources for delivering a product or service to the customer. A release plan is not a risk response, but rather a communication or scope management tool.

A validation check is a process that verifies that the project deliverables meet the customer’s needs and expectations. A validation check is not a risk response, but rather a quality control or assurance activity. References = CompTIA Project+ Study Guide: Exam PK0-005, 3rd Edition, Chapter 10: Executing and Closing Projects, page 314; CompTIA Project+ Certification Exam Objectives, Domain 3: Project Execution, Objective 3.2: Given a scenario, execute and monitor project tasks using traditional methodologies; Backout Plan - DevX