When using RADIUS as an external authentication method for 802.1X authentication for the Junos Pulse Access Control Service, what must you do to ensure that the RADIUS authentication works properly?（）

• A、Configure IP helper to forward the authentication requests from the clients to the external RADIUS server
• B、Configure the supplicant as anexternal authentication server
• C、Configure RADIUS proxy on the realm
• D、Specify the correct RADIUS port 389 on the Junos Pulse Access Control Service