Final answer:
Virtualization is the process of using special software to create a virtual machine environment that functions as a separate computer.
Step-by-step explanation:
The correct answer is a) Virtualization. Virtualization is the process of using special software (hypervisors or visual machine managers) to create a complete environment in which a guest OS can function as though it were installed on its own computer. The guest environment created is called a virtual machine (VM).