Final answer:
To remove a line from an invoice, one can click on a field and press the delete key, use the Edit menu, or use specific commands like 'del :.b' in the command line, if the software supports these methods.
Step-by-step explanation:
To remove a line from the invoice, you can use several methods as described in your options. It is generally possible to click on a field and press the delete key to remove a line, or you could use the Edit menu options to remove a specific line. Additionally, the command line can be a powerful tool for performing specific changes. To activate the command line, you would go to the Tools menu, choose the General Controls sub-menu, and use the command del : followed by .b to delete a line. The command focus could be used to navigate fields. However, which methods are actually available to you will depend on the specific software or application you are using. If the software offers all these methods, then the correct answer would be option 4: All of the above methods will remove the line.