The correct answer is: B. cpu, memory & i/o
A virtual machine monitor (VMM), also known as a hypervisor, is a software program that creates and runs virtual machines (VMs). A VM is a software implementation of a computer that executes programs like a physical machine.
VMMs facilitate sharing of CPU, memory, and I/O resources among multiple VMs. This allows multiple operating systems to run on a single physical machine, which can improve resource utilization and provide isolation between different applications.
Option A is incorrect because it only mentions memory and I/O. Option C is incorrect because it only mentions CPU and memory. Option D is incorrect because it only mentions I/O and CPU.