Which of the following best describes a rollback plan?

A rollback plan (sometimes called a “backout plan”) defines the steps to revert a system to the last known good/operational state if an implemented change fails or creates unacceptable impacts. That is exactly what option B states: returning to the operational state before the change was applied. This aligns with IT change control practices emphasized in Project+ governance and change control contexts, where changes must include consideration for restoring service quickly if outcomes are not as expected.

Option A (“apply an alternative plan”) is closer to a general contingency/fallback plan, which may involve a different solution path rather than undoing the change. Options C and D are not standard control responses: restarting the entire project is extreme and unrelated to change backout, and repeating tasks “until they work” ignores risk control and service stability.

In project environments—especially IT—rollback planning is part of responsible change implementation because it reduces downtime, protects users, and supports controlled deployment. If validation/testing after the change shows failure, the rollback plan provides a predefined, approved path to quickly restore the prior baseline while the team reassesses or submits a revised change request.