Deep packet inspection (DPI) is a core capability of data loss prevention (DLP) tools that allows the analysis of the content of data packets in transit. This helps detect the unauthorized movement of sensitive data by examining packet-level details. * Network Traffic Logs (Option A):These provide historical data but do not actively detect data in transit. * Data Inventory (Option C):Useful for identifying where sensitive data resides but not for monitoring its movement. * Proprietary Encryption (Option D):Protects data but does not detect unauthorized transmission. Reference:ISACA CISA Review Manual, Job Practice Area 4: Protection of Information Assets.