The CIO of a company interested in IP telephony is concerned that an IP telephony solution will not work with third-party software and hardware. Which of these is the best response to this concern?
A.
Cisco IP telephony solutions can effectively replace functionality provided by third-party software and hardware
B.
Cisco IP telephony solutions maintain interoperability through the use of a single-vendor network.
C.
Cisco IP telephony solutions work with third-party PBX hardware and software.
D.
Cisco IP telephony solutions are open standards-based.