Which type of file can potentially contain data about previously printed documents?

The spool file is the correct choice because it serves as a temporary storage area for print jobs before they are sent to the printer. When a document is printed, the operating system creates a spool file that contains a copy of the document in a format that the printer can understand. This file allows the system to manage multiple print jobs efficiently by queuing them for printing. As a result, previously printed documents can sometimes be found in the spool file until it is cleared or deleted, making it a potential source of information regarding past prints.

In contrast, the other types of files mentioned do not primarily function as repositories for previously printed documents. The swap file, for instance, is used to store data that does not fit in the computer's RAM. The EMF (Enhanced Metafile) file is a graphics file format used primarily for representing images, including vector graphics, but does not serve the same purpose as a spool file. The pagefile.sys is a Windows system file used for virtual memory, which temporarily holds data that is not currently in use by the RAM. While it may contain data related to many processes, it does not specifically retain records of printed documents like the spool file does.