Questions: John works as a security manager at XYZ Inc. He has created a policy to allow employees to use their personally owned devices. He is getting reports of the company's data appearing on unapproved forums and an increase in the theft of personal electronic devices. Which of the following security controls would he implement to reduce the risk of exposure?

The answer is the first one (A): Disk encryption on the local drive.

Explanation for each option:

A. Disk encryption on the local drive: This option is correct because encrypting the data on the local drive of personal devices ensures that even if the device is stolen, the data remains protected and inaccessible to unauthorized users. This helps in reducing the risk of data exposure if personal devices are lost or stolen.

B. Implementation of S/MIME: S/MIME (Secure/Multipurpose Internet Mail Extensions) is primarily used for securing email communications by providing encryption and digital signatures. While it enhances email security, it does not directly address the issue of data exposure from stolen devices or data leaks on forums.

C. Parity checking: Parity checking is a method used to detect errors in data transmission or storage. It is not relevant to the problem of data exposure on forums or theft of devices, as it does not provide any encryption or protection for the data itself.

In summary, implementing disk encryption on personal devices is the most effective control to reduce the risk of data exposure due to theft or unauthorized access.