Which command is used to enable timestamp in real-time debug?

The command "diagnose debug console timestamp enable" is the correct choice for enabling timestamps in real-time debug on a Fortinet device.

The use of this command is specifically designed for the debug console, allowing administrators to see when each log entry or debug message is generated. This can be crucial for troubleshooting and understanding the sequence of events that occur during operations and is especially helpful when trying to diagnose issues in a time-sensitive manner.

The format of the command highlights the "diagnose" prefix, which indicates a diagnostic level command geared towards real-time debugging tasks. Timestamps provide a clear context that can significantly aid in correlating actions and responses, making it easier to pinpoint issues or understand system behavior accurately during the diagnostics session.

In contrast, the other options provided do not correctly reflect the appropriate syntax or function dedicated to enabling timestamps in real-time debug scenarios. Understanding the correct command structure is key to effective network management and troubleshooting with Fortinet devices.