The correct answer is: A. cat
The cat command is used to display the contents of a file or concatenate multiple files together. It can also be used to create a new file.
The vi command is a text editor that can be used to create and edit files.
The ed command is a line editor that can be used to edit files.
The lyrix command is a music player that can be used to play music files.
None of the above commands can be used to both display and create files.