Which of the following terms BEST describes the software or hardware used to manage virtual machines?

A hypervisor (also called a Virtual Machine Monitor) is the core technology that abstracts physical hardware and allocates resources to multiple virtual machines. It exists in two forms - Type 1 (bare-metal, e.g., Hyper-V, VMware ESXi) runs directly on hardware, and Type 2 (hosted, e.g., VirtualBox) runs atop an existing OS, but both serve the role of VM management.

Cloud Server Manager is not a standard industry term for the software that manages virtual machines at the hypervisor level.

Supervisor is a generic computing term referring to an OS kernel or process monitor, not the specific technology used to manage virtual machines.

Virtual Disk Manager refers to tools that manage virtual hard disk files, not the broader platform responsible for running and managing entire virtual machines.