The best way to reduce the risk associated with a bring your own device (BYOD) program is to implement a mobile device management (MDM) solution. Therefore, the correct answer is option C.

C. Implement a mobile device management (MDM) solution.

Implementing a mobile device policy and standard is the best way to reduce the risk associated with a bring your own device (BYOD) program. The policy should outline the acceptable use of mobile devices in the workplace and establish guidelines for securing sensitive information and complying with regulatory requirements. The standard should specify the minimum technical requirements for mobile devices, such as encryption, password protection, and anti-malware software, and should also outline the steps that employees must take to secure their devices and protect sensitive information. By establishing a clear policy and standard, the organization can ensure that all mobile devices are used in a secure and compliant manner, which will help to reduce the risk of a security breach. The policy and standard should be communicated to employees and reinforced through training and awareness programs.

From the CISM Review Manual, 15th Edition, by ISACA: "The information security manager should ensure that an appropriate level of control is maintained for all mobile devices that access corporate resources. Mobile device management (MDM) systems can provide control over mobile devices, allowing the organization to enforce policies, manage device settings, monitor compliance with corporate policies, and remotely wipe or lock lost or stolen devices."

Implement MDM

Implementing a mobile device policy and standard is the best way to reduce the risk associated with a bring your own device (BYOD) program. A mobile device policy and standard provides clear guidelines for employees on what is expected of them when using their own devices for work purposes. This includes guidelines for secure device configuration, password protection, software updates, and acceptable use of the device. The policy and standard also provide clear instructions on what to do in the event of a lost or stolen device, data breach, or other security incident. By establishing a clear policy and standard for mobile device use, organizations can reduce the risk of security incidents and ensure that sensitive information is protected.

implement the MDM

I opted A because i think it should be in your policy to use MDM first. Then you implement and configured a solution according to standard. So A encompasses C, but i have seen here the solution is oftenly techincal.

I always go with technical solutions as policies will not always be followed

As per johndeer11 answer with ISACA ref.

Option C

may be use of FIRST instead of BEST in the question so not to choose MDM as the answer