The correct answer is D. PC.
A PC, or personal computer, is a general-purpose single-user microcomputer designed to be operated by one person at a time. PCs are typically used for tasks such as word processing, spreadsheets, presentations, and internet browsing. They can also be used for more specialized tasks such as gaming, video editing, and music production.
A special-purpose computer is a computer that is designed to perform a specific task or set of tasks. For example, a supercomputer is a special-purpose computer that is designed to perform complex calculations. A KIPS, or kiloinstruction per second, is a unit of measure for the speed of a computer. An M is a unit of measure for memory.
None of the other options are correct.