Which two of the following statements are true about VPIM?

A.	VPIM is used to exchange email messages between different voice-mail systems.
B.	voice-mail systems that are using VPIM must have unique extensions.
C.	VPIM must use a location ID for each voice-mail system.
D.	VPIM must be used when internetworking Cisco Unity Connection and Cisco Unity Express.
E.	VPIM users cannot be regular voice-mail users.
F.	VPIM message use a similar format to SIP SDP messages, as defined in RFC 3281.