List three types of services a network might support th...
单项选择题List three types of services a network might support that are considered part of unified communications or convergence.（）
A.File transfers, print services, and conversational voice
B.User authentication, streaming live audio and video, and print services
C.Web services, email services, and file services
D.Conversational voice, streaming live audio and voice, and streaming stored audio and voice
