Providing assurance on risk management processes is the activity that should only be performed by the third line of defense, because it is the role and responsibility of the independent andobjective assurance function, such as internal audit or external audit, to evaluate and report on the effectiveness and efficiency of the risk management processes and controls. The third line of defense is the last layer of the three lines of defense model, which is a framework that defines the roles and responsibilities of different functions and levels within the organization for risk management and control. The first line of defense is the operational management and staff, who are responsible for identifying, assessing, and managing the risks and controls within their areas of responsibility. The second line of defense is the oversight and support functions, such as risk management, compliance, or legal, who are responsible for establishing and monitoring the risk policies, standards, and frameworks, and providing guidance and advice to the first line of defense. The third line of defense is the assurance function, who are responsible for providing independent and objective assurance on the adequacy and effectiveness of the risk management processes and controls, and reporting to the senior management and the board of directors. Operating controls for risk mitigation, testing the effectiveness and efficiency of internal controls, and recommending risk treatment options are all activities that can be performed by the first or second line of defense, but not by the third line of defense, as they are not part of the assurance function. References = Risk and Information Systems Control Study Manual, Chapter 2, Section 2.4.1, page 59