Which of the following statements is true regarding ad-hoc conferences for endpoints without Cisco VCS?

A.
H.323 endpoints can neither initiate nor be added to an ad-hoc conference.

B.
H.323 endpoints cannot initiate an ad-hoc conference but can be added to an ad hoc conference.

C.
H.323 endpoints can initiate an ad-hoc conference but cannot be added to an ad hoc conference.

D.
H.323 endpoints can initiate an ad-hoc conference and can be added to an ad-hoc conference.

Explanation:
323 endpoints without Cisco TelePresence Video Communication Server (VCS) cannot initiate an ad-hoc
conference but can be added to an ad-hoc conference by a Session Initiation Protocol (SIP) endpoint.
Alternatively, H.323 endpoints can initiate an ad-hoc conference by using Multiway with Cisco VCS.
Ad-hoc conferences are also known as unscheduled or on-demand conferences. To participate in an ad-hoc
conference, simply press the Conf, Join, cBarge, or Add keys on the endpoint.
SIP endpoints can initiate an ad-hoc conference and can be added to an ad-hoc conference. A SIP endpoint is
required to add an H.323 endpoint to an ad-hoc conference without Cisco VCS.
Either MultiSite or Multiway can be used for ad-hoc conferences, which are also called on-demand
conferences. MultiSite uses a phone’s native multipoint control unit (MCU) functionality and allows up to four
participants in a conference. However, MultiSite requires that an option key be installed on each endpoint.
Multiway allows many more participants but requires a Cisco VCS and a Cisco TelePresence MCU to handle
the conference. In addition, an option key is not required for Multiway. MultiSite and Multiway are mutually
exclusive; if Multiway is used on your network, you should disable MultiSite on the endpoints.

Cisco: Cisco Rich Media Conferencing: Ad-hoc Audio Conference