A:Answer Hi Stacy,
Yes - Speaker A+B can be selected. With Speaker A+B selected, you would have five speakers in the surround set-up, as the 6th and 7th speakers would be assigned as the front B speakers.
Here is a link with how this is done:
https://manuals.denon.com/AVRX1700H/NA/EN/GFNFSYvqscamxo.php#WBSPMLgwuqitsb