how many segments are being reserved on the Cisco TelePresence Multipoint Switch?

Given the following:
Cisco TelePresence endpoint A: CTS-3000
Cisco TelePresence endpoint B: CTS-1000
Cisco TelePresence endpoint C: CTS-1300
Cisco TelePresence endpoint D: CTS-1000
For a multipoint meeting scheduled between these endpoints, only endpoint A calls in. If this is the only meeting currently active, how many segments are being reserved on the Cisco TelePresence Multipoint Switch?

A.
0

B.
1

C.
3

D.
6

E.
8