The most effective key risk indicator (KRI) for monitoring risk related to a bring your own device (BYOD) program is the number of incidents originating from BYOD devices, as it directly measures the impact and frequency of the potential threats and vulnerabilities associated with the use of personal devices for accessing company data and systems. A BYOD program can pose various risks to an organization, such as data loss or breach, malware infection, unauthorized access, compliance violation, or device theft or loss12. The number of incidents originating from BYOD devices can help to identify and quantify these risks, and to trigger appropriate risk response actions when the incidents exceed the acceptable thresholds. The other options are not the most effective KRIs, as they do not directly measure the risk level or impact of the BYOD program. The number of users who have signed a BYOD acceptable use policy may indicate the awareness and compliance of the users, but not the actual risk exposure or mitigation. The budget allocated to the BYOD program security controls may indicate the investment and efficiency of the risk management, but not the effectiveness or necessity. The number of devices enrolled in the BYOD program may indicate the scope and scale of the risk, but not the severity or likelihood. References = Key Risk Indicators: A Practical Guide; KRI Framework for Operational Risk Management