Which two of the following methods can be used to challenge the identity of a TelePresence endpoint from a Cisco Unified Communications Manager servers?

Which two of the following methods can be used to challenge the identity of a TelePresence
endpoint from a Cisco Unified Communications Manager servers? (Choose two)

A.
PKI

B.
TLS

C.
SRTP

D.
Digest authentification

E.
HTTPS

F.
SFTP