What command would be used to display the contents of a file?

The command used to display the contents of a file is "cat." This command reads the specified file and outputs its content to the standard output, which is usually the terminal or command line interface. It is one of the most commonly used commands for quickly viewing the contents of text files in Linux. Additionally, "cat" can be used to concatenate multiple files together and display them sequentially, which provides versatility beyond just displaying a single file's content.

The other commands listed serve different purposes. For example, "ls" is used to list the files and directories in a specified directory, providing a snapshot of the contents rather than the content of individual files. The "touch" command is primarily used to create empty files or update the timestamps of existing files but does not display any file content. Lastly, "cp" is a command used for copying files or directories from one location to another, which is unrelated to displaying a file’s content. Thus, cat is the appropriate command for this task.