Which of the following statements is true about word processing programs?

Newer versions of word processing programs cannot save files in the older $.$doc format.

New features in MS Word $2007,$ such as the ability to format citations in a variety of styles, are retained when the file is saved in the $.$doc format.

Older versions of MS Wordimcan be adapted to read the newer $.$docx file formats by downloading and installing a compatibility program that is available at a price from Microsoft's Web site.

Document file extensions are displayed by default in the Windows operating system.

Instructions for displaying the file extensions are available from the operating system's help menu.