The best approach to mitigate the risk associated with a control deficiency is to implement compensating controls. A control deficiency is a situation where a control is missing, ineffective, or inefficient, and cannot provide reasonable assurance that the objectives or requirements are met. A compensating control is a control that provides an alternative or additional measure of protection when the primary or preferred control is not feasible or effective. A compensating control can help to reduce the likelihood and/or impact of the risk associated with the control deficiency, and maintain the compliance or performance level. The other options are not as effective as implementing compensating controls, as they are related to the analysis, assessment, or provision of the risk, not the mitigation of the risk. References = Risk and Information Systems Control Study Manual, Chapter 3: IT Risk Response, Section 3.3: IT Risk Response Implementation, page 145.