What type of clients does a Network Operating System serve?

A Network Operating System (NOS) is designed to manage network resources and provide services to multiple users simultaneously. This is integrated into environments where various users may have different requirements and access levels.

The correct response focuses on the capability of a NOS to handle diverse client needs, such as file sharing, printer access, and database services, for numerous users concurrently. This support for multiple simultaneous requests is essential for environments like businesses or schools, where many users might need access to shared resources at the same time.

In contrast, the other options suggest limitations that do not align with the comprehensive service provided by a NOS. For example, serving only single users or guests with restricted access would not utilize the full potential of a network environment, whereas servicing only administrative users would severely limit usability and collaboration within an organization. Therefore, the right answer reflects the versatility and multi-user support that defines a Network Operating System's role in managing and facilitating network activities.