Explanation:

A supercomputer is a computer that performs at or near the currently highest operational rate for computers. Traditionally, supercomputers have been used for scientific and engineering applications that must handle very large databases or do a great amount of computation (or both).
Mainframe computers or mainframes (colloquially referred to as "big iron") are computers used primarily by large organizations for critical applications; bulk data processing, such as census, industry and consumer statistics, enterprise resource planning; and transaction processing.
A microcomputer is a small, relatively inexpensive computer with a microprocessor as its central processing unit. It includes a microprocessor, memory and minimal input/output circuitry mounted on a single printed circuit board.
Hence, option 3 is the correct answer.