10. Network syster with a a building or campus is A. LAN B. WAN C. MAN D. Nene of the above.

To solve the problem, we need to identify the type of network system that is typically used for a building or campus. Here are the definitions of the options provided: A. **LAN (Local Area Network)**: This is a network that connects computers and devices in a limited geographical area, such as a single building or a campus. B. **WAN (Wide Area Network)**: This type of network covers a broad area, often connecting multiple LANs over long distances. C. **MAN (Metropolitan Area Network)**: This network covers a larger area than a LAN but is smaller than a WAN, typically spanning a city or a large campus. D. **None of the above**: This option suggests that none of the previous options are correct. Given that a building or campus is typically connected using a LAN, the correct answer is: **A. LAN**