The configuration shown in the exhibit indicates that the FortiGate is using a Fortinet-specific RADIUS attribute (Fortinet-Group-Name) with the value "Training." This setup allows the FortiGate to authenticate users against the RADIUS server and match them to the "Training" Organizational Unit (OU). By doing so, only users within this specific group or OU can be authenticated and allowed access through the FortiGate.
Reference:
FortiOS 7.4.1 Administration Guide: RADIUS Server Configuration

The debug output indicates that FortiGate connected to one server (173.243.141.16) to retrieve contract information as it shows four FortiGuard requests without any packet loss, which confirms the connection to the server. Additionally, the default FortiGuard communication settings are being used, as indicated by the use of the HTTPS protocol on port 443, which is the default setting for FortiGuard connections.
References:
* FortiOS 7.4.1 Administration Guide: FortiGuard Connection Settings

A. Services defined in the firewall policy
C. Destination defined as Internet Services in the firewall policy
E. Source defined as Internet Services in the firewall policy
When a packet arrives, how does FortiGate find a matching policy? Each policy has match criteria, which you can define using the following objects:
* Incoming Interface.
* Outgoing Interface.
* Source: IP address, user, internet services.
* Destination: IP address or internet services.
* Service: IP protocol and port number.
* Schedule: Specific times to apply policy.

By default, DNS queries to FortiGuard servers use UDP port 53.