Which of the Following Statements Regarding RADIUS Are True

Which of the following statements regarding RADIUS are true?

A) Authentication, authorization, and accounting are separated in RADIUS protocol.
B) RADIUS authentication, and Portal authentication cannot be used together because users can be authenticated using the Portal server when Portal authentication is enabled.
C) MAC address authentication does not require a user name and password. Therefore, users cannot be authenticated through RADIUS when using MAC address authentication.
D) RADIUS supports user access in wired and wireless modes.