I installed Adobe Acrobat DC today and I am a novice user. I need to split thousands of PDF files into a separate PDF file for every bookmark and there are usually about twenty bookmarks per file.. I select menu items VIEW > TOOLS > ORGANIZE PAGES > OPEN It asks me to open a single file wtth no option to open multiple files. The "Split" option appears in an upper toolbar but it is faint and disabled. How can I find the option to open multiple files rather than the optio to open a single file?.