Datagram networks and virtual-circuit networks differ in ____. A. Datagram networks are circuit-switched networks, and virtual-circuit networks are packet-switched networks. B. Datagram networks are packet-switched networks, and virtual-circuit networks are circuit-switched networks. C. Datagram networks use destination addresses and virtual-circuit networks use VC. Numbers to forward packets toward their destination. D. Datagram networks use VC. Numbers and virtual-circuit networks use destination addresses to forward packets toward their destination.