The PRIMARY reason for an organization to ensure the risk register is updated regularly is to make sure that risk information is available to enable risk-based decisions, because the risk register is a tool that documents and tracks the identified risks, their characteristics, their status, and their responses. The risk register provides a comprehensive and current view of the risk profile and exposure of the organization, and it supports the decision-making process and the risk management activities. The other options are not the primary reason, because:
* Option A: Risk assessment results are accessible to senior management and stakeholders is a benefit of updating the risk register regularly, but not the primary reason. Risk assessment results are the outputs of the risk analysis process, and they should be recorded and communicated to the relevant parties, but they are not the only or the most important information in the risk register.
* Option B: Risk mitigation activities are managed and coordinated is a result of updating the risk register regularly, but not the primary reason. Risk mitigation activities are the actions taken to address the identified risks, and they should be monitored and reported in the risk register, but they are not the only or the most important information in the risk register.
* Option C: Key risk indicators (KRIs) are evaluated to validate they are still within the risk threshold is a process that involves updating the risk register regularly, but not the primary reason. KRIs are indicators that measure and monitor the risk exposure and performance of the organization, and they should be compared with the risk threshold to determine if the risk level is acceptable or not, and if any action is required, but they are not the only or the most important information in the risk register. References = Risk and Information Systems Control Study Manual, 7th Edition, ISACA, 2020, p. 108.