Selected Answer: A Correct Answer: A (periodic client connection) Explanation In Harmony Endpoint, a heartbeat is the regular communication started by the endpoint client with the Harmony Endpoint Management server. This communication is used to: Verify that the client is alive and connected Report status and health information Receive policy updates Send logs and telemetry Check for commands from the management server Why not B? Although the default heartbeat interval is 60 seconds, the question is asking for the definition of heartbeat, not its default timing.