Early in the project several mitigation actions were not executed promptly, causing schedule impact and stakeholder frustration. What should you have done to manage the issue?

The correct answer is "Identified the appropriate response and ensured its implementation." This option encompasses the proactive and complete management of risks that have become issues. Identifying the appropriate response involves developing a plan to address the issue, and ensuring its implementation means executing that plan. Simply identifying and reporting the issue (option 1) is insufficient; it doesn't solve the problem. Monitoring and controlling the issue (option 2) is part of the process but assumes a response has already been implemented and needs oversight. Communicating actions to stakeholders (option 4) is crucial but is a step after the response has been identified and is being implemented, not the primary action to manage the issue itself.