Virtualization allows multiple independent operating systems and applications to run on the same physical server, each inside its own virtual machine. It also introduces logical switching so traffic can move between virtual machines on the same host and out to the physical network through a physical NIC. This is why network engineers must understand virtual switches, port groups, VLAN tagging, and hypervisor uplinks. Cisco CCNA 200-301 v1.1 includes virtualization in Network Fundamentals because modern campus and data-center traffic often begins or ends inside a virtualized host. The environment does not require a dedicated hypervisor used only as an SNMP network manager, and a physical router does not directly connect to each VM NIC. Virtualization also does not require systems to reside on the internet. The core points are resource abstraction and logical connectivity. Multiple OS instances share one physical hardware platform, and virtual network devices move traffic between VMs and the physical network. That makes B and C correct.