which of the following?

Frame relay and X.25 networks are part of which of the following?

A.
Circuit-switched services

B.
Cell-switched services

C.
Packet-switched services

D.
Dedicated digital services

Explanation:
Packet-Switched Technologies:
X.25
Link Access Procedure-Balanced (LAPB)
Frame Relay
Switched Multimegabit Data Service (SMDS)
Asynchronous Transfer Mode (ATM)

Voice over IP (VoIP)