What command would you use to copy a file in Linux?

The command used to copy a file in Linux is "cp." This command stands for "copy" and is a standard Unix command that allows users to create a duplicate of a file or directory. When you use "cp," you can specify the source file and the destination where you want to create the copy. The syntax is typically cp [source] [destination], making it a straightforward and efficient way to manage file duplication within the file system.

The other options presented are not standard Linux commands for copying files. "copy" is a command used in some other operating systems, particularly Windows, but it does not exist in Linux. The "mv" command is used for moving files or directories from one location to another rather than copying them. "duplicate" is not a recognized command in Linux and would not produce the desired outcome of copying files. Therefore, "cp" is the correct and appropriate command for this task in a Linux environment.