Which of the following is a form of virtualization that separates a physical machine into multiple virtual machines?

The correct option is 'Hypervisor.' A hypervisor is a type of virtualization technology that allows a single physical machine to run multiple virtual machines. These virtual machines, or VMs, are isolated from each other and from the host system. The hypervisor controls and allocates hardware resources to these VMs, making it an efficient solution for server virtualization. Virtual Private Networks (VPNs) are not related to machine virtualization. Emulation often replicates a specific environment for compatibility, while containerization is a different virtualization method where applications share the same OS kernel.