If you look at the parking map Area B is the outer part of the mall where the office buildings are and Area A is in close to the venue.
The problem it appears is that if you follow the link from the Merriweather site to get the parking pass for this show it shows both Area's are sold out. I think it's because the page for the parking passes is still marked as the event being postponed and they never updated it.
If you look at remaining events you can still get at least Area B for those show, so I think for tonight's show unless you got the pass when the show went on sale, you can't now.
Having never been to MPP since they changed all the parking up there, I have no idea if they even check for parking passes or just check to see if you have a ticket.
No clue on whether or not you can park at the mall other than what's outlined on their website.
https://merriweathermusic.com/parking/Looks like Area C & D are only used for festivals..