How can I Save As PDF 1.4/A in Acrobat XI Standard

I have Adobe Acrobat XI Standard.  I am trying choose and save some documents as PDF 1.4/A for archiving.  When I go to save I do not have the option to save in previous versions of Acrobat PDF, just PDF or JPG, HTML, TIFF etc.  I want to specifically have a 1.4/a PDF.  Oddly enough I have that option for scanning documents with the scanner.  But what to do if it isn't created from a scanner? I did a basic install of Acrobat XI Standard.