The correct answer is "File, Save As" because to rename a file, you need to go to the "File" menu and select the "Save As" option. This allows you to save the file with a different name or in a different location. The other options, "Contrl-S" and "Cntrl-X" are keyboard shortcuts for saving and cutting, respectively, but they do not specifically rename the file. Therefore, the correct option is "File, Save As."