C - A single computer with a single user is typical of a mainframe computer.
Explanation:
Mainframes are a type of computer that generally are known for their large size, amount of storage, processing power and high level of reliability. They are primarily used by large organizations for mission-critical applications requiring high volumes of data processing. In general, there are a few characteristics of mainframes that are common among all mainframe vendors: Nearly all mainframes have the ability to run (or host) multiple operating systems. Mainframes can add or hot swap system capacity without disruption. Mainframes are designed to handle very high volume input and output (I/O) and emphasize throughput computing. A single mainframe can replace dozens or even hundreds of smaller servers.
