正解:C
The command show file system is used on Cisco devices to display a list of all the file systems available. This command provides information about each file system, including its name, size, free space, and file system type (such as flash or nvram). It's a useful command for network administrators to manage and navigate through different storage areas on Cisco devices, ensuring they can access and maintain the device's file structure effectively. Reference := File System Commands on Cisco IOS XR Software - Cisco, Working with the Cisco IOS File System, Configuration Files, and Software Images