What happens when Cisco TelePresence endpoint A calls Cisco TelePresence endpoint B?

Given the following:
Cisco TelePresence endpoint A:
Phone field: Disable Speakerphone and Headset is checked. ON configuration: Auto answer is enabled.
Cisco TelePresence endpoint B:
Phone field: Disable Speakerphone and Headset is unchecked. ON configuration: Auto answer is enabled.
What happens when Cisco TelePresence endpoint A calls Cisco TelePresence endpoint B?

A.
Cisco TelePresence endpoint A gets a fast busy.

B.
Cisco TelePresence endpoint B gets a ring, and the call will establish as an audio-only call out of the Cisco IP Phone.

C.
Cisco TelePresence endpoint B gets a ring, and the call will establish as a video-only call.

D.
Cisco TelePresence endpoint B gets a ring, and the call will establish , but there is no audio
or video.