Which two characteristics of the TACACS+ protocol are true?

Which two characteristics of the TACACS+ protocol are true? (Choose two.)

A.
uses UDP ports 1645 or 1812

B.
separates AAA functions

C.
encrypts the body of every packet

D.
offers extensive accounting capabilities

E.
is an open RFC standard protocol

Explanation:
http://www.cisco.com/en/US/tech/tk59/technologies_tech_note09186a0080094e99.shtml
Packet Encryption

RADIUS encrypts only the password in the access-request packet, from the client to the server. The
remainder of the packet is unencrypted. Other information, such as username, authorized services,
and accounting, can be captured by a third party.
TACACS+ encrypts the entire body of the packet but leaves a standard TACACS+ header. Within the
header is a field that indicates whether the body is encrypted or not. For debugging purposes, it is
useful to have the body of the packets unencrypted. However, during normal operation, the body of
the packet is fully encrypted for more secure communications.
Authentication and Authorization RADIUS combines authentication and authorization. The accessaccept packets sent by the RADIUS server to the client contain authorization information. This makes
it difficult to decouple authentication and authorization.
TACACS+ uses the AAA architecture, which separates AAA. This allows separate authentication
solutions that can still use TACACS+ for authorization and accounting. For example, with TACACS+, it
is possible to use Kerberos authentication and TACACS+ authorization and accounting. After a NAS
authenticates on a Kerberos server, it requests authorization information from a TACACS+ server
without having to re-authenticate. The
NAS informs the TACACS+ server that it has successfully authenticated on a Kerberos server, and the
server then provides authorization information.
During a session, if additional authorization checking is needed, the access server checks with a
TACACS+ server to determine if the user is granted permission to use a particular command. This
provides greater control over the commands that can be executed on the access server while
decoupling from the authentication mechanism.