The correct answer is c) Click File, Save as.
Clicking File and then Save as will allow you to save a document with a new name. This option will prompt you to choose a file name and file location, and then save the document with the new name and in the desired location.
Pressing Ctrl + S and clicking File and then Save will only save the document with its current file name and location, overwriting any previous changes made to the document.
Clicking Tool and then Save is not a common way to save a document and may not be available in all software programs.