Which of the following options is correct for describing the effect of each role in the Portal authentication system?

Which of the following options is correct for describing the effect of each role in the Portal authentication system?
A . The client is Any Office software.
B . The role of the Portal server is to receive client authentication requests, provide free portal services and authentication interfaces, and exchange client authentication information with the access device.
C . The role of the RADIUS server is to redirect all HTTP requests from users in the authentication network segment to the Portal server.
D . The role of the admission control device is to complete user authentication, authorization and accounting.

Answer: B