The correct answer is C. vmm.
A virtual machine monitor (VMM) is a software program that creates and runs virtual machines. A virtual machine is a software program that behaves like a physical computer, with its own CPU, memory, storage, and network interface. VMMs allow multiple operating systems to run on the same physical computer, each in its own virtual machine. This can be useful for running different operating systems for different tasks, or for running multiple copies of the same operating system for testing or development purposes.
VGM stands for Virtual Guest Machine. It is a type of virtual machine that is used to run guest operating systems on a host operating system. VGMs are typically used for testing or development purposes, or to run legacy operating systems that are no longer supported by the host operating system.
VMC stands for Virtual Machine Client. It is a software program that allows users to connect to and interact with virtual machines. VMC clients are typically used by system administrators to manage virtual machines, or by users to access their virtual machines from remote locations.
All of the mentioned options allow different operating systems to run in their own memory space. However, VMM is the most general term, and it can be used to refer to any type of virtual machine monitor. VGM and VMC are specific types of VMMs that are used for different purposes.