正解:B
A vSwitch, or virtual switch, enables VMs to communicate with each other within a virtualized server. It is a software-based network switch that operates within a virtualized environment, bridging virtual machines (VMs) and physical network interfaces. Unlike a hardware switch, it does not support advanced Layer 3 routing protocols, does not have higher performance than a hardware switch, and does not operate as a hub broadcasting traffic to all vPorts.