Which of the following recent trends can be defined as the abstraction of different computing resources like processor, Memory etc, and is the single most effective way to reduce IT expenses?

The correct answer is D, Virtualization. Virtualization creates a software layer over the physical processor, memory and storage of a machine, so that one server can be divided into several virtual machines, each running its own operating system as though it had hardware of its own. The program that makes this possible is the hypervisor. Because a single strong server then does the work of many lightly used ones, organisations buy less hardware and spend less on power, cooling and floor space, which is why it is called the most effective way to cut IT costs. It is also the base on which cloud computing is built. Option A is wrong because artificial intelligence is about machines doing tasks that need human-like reasoning. Option B is wrong because clustering joins several computers to work as one for speed and reliability, not to abstract resources. Option C is wrong because a storage area network is a dedicated network for storage alone. Exam tip: hypervisor runs virtual machines, and virtualization underlies cloud computing.