During an annual review of security policies, a company discovered that multiple incidents related to data leakage were a result of employees accidentally sending proprietary information to external contacts. Which of the following would be the BEST approach to mitigate this type of unintentional data loss?
Enforce more stringent role-based access controls on proprietary data.
Implement data loss prevention (DLP) systems that can detect and block sensitive data from being sent via email.
Increase the frequency of employee training on the acceptable use policy and proper data handling.
Review and update the procedures for external communications to include stricter guidelines.