The correct answers are A and D.

The debug output shows:

Sent RADIUS req to server 'RadiusServer': IP=172.25.188.164 ... user='student' using CHAP

Result for radius svr 'RadiusServer' 172.25.188.164(0) is 0

Sending result 0 for req 2

The study guide explains that in RADIUS real-time debug, FortiGate shows the IP address of the RADIUS server it is querying. In the example, it says FortiGate ''creates an access request to the RADIUS server at IP address 10.0.13.130'' and shows the line Sent radius req to server ... IP=10.0.13.130

So in your exhibit, the queried server is clearly 172.25.188.164, which makes A correct.

The study guide also states:

''The message fnbamd_comm_send_result-Sending result 0 indicates that the authentication was successful and that FortiGate received the Access-Accept message.''

Since your exhibit also ends with Sending result 0, that makes D correct.

Why the other options are wrong:

B is wrong because result 0 means authentication successful, not failed

C is wrong because the debug explicitly shows using CHAP, and the study guide lists supported RADIUS schemes as CHAP, PAP, MS-CHAP, and MS-CHAPv2

E is wrong because the study guide says two-factor authentication would involve an Access-Challenge response: ''If two-factor authentication is enabled on the server, the response is an Access-Challenge message''

Your exhibit shows successful result 0 / Access-Accept, not a challenge.

So the verified answers are: A, D.