Which technology allows multiple operating systems to run on a single physical host?

Server virtualization is the correct answer because it enables a single physical server to host multiple virtual machines (VMs), each running its own operating system independently. This technology abstracts the hardware resources of the physical server, such as CPU, memory, and storage, and allocates them to the VMs. Virtual routing and forwarding (VRF) is incorrect because it's a technology used in networking to create multiple routing tables within a single router, isolating traffic for different customers or departments. Virtual device contexts (VDCs) are a Cisco Nexus-specific feature that partitions a single physical switch into multiple logical switches, primarily for administrative separation. Network Port ID Virtualization (NPIV) is a Fibre Channel technology that allows a single physical Fibre Channel host bus adapter (HBA) port to register multiple NPort IDs with a Fibre Channel switch, primarily for storage area networks. These options do not directly address running multiple operating systems on a single physical host.