正解:B
A virtual machine (VM) is an emulation of a computer system that provides the functionality of a physical computer. To run a VM, you need a hypervisor, which is software that creates and runs virtual machines. The hypervisor sits between the hardware and the VM and allocates physical resources such as CPU, memory, and storage to the VM. There are two types of hypervisors:
* Type 1 hypervisor: Also known as a bare-metal hypervisor, it runs directly on the host's hardware to control the hardware and to manage guest operating systems. Examples include VMware ESXi, Microsoft Hyper-V, and Xen.
* Type 2 hypervisor: Also known as a hosted hypervisor, it runs on a conventional operating system just like other computer programs. Examples include VMware Workstation and Oracle VirtualBox.
While a Type 1 hypervisor does not require a host operating system, a Type 2 hypervisor does. Therefore, the correct answer is B, as a hypervisor (either Type 1 or Type 2) and physical server hardware are required to run a VM.