You could maybe get to all B's, or some B's and some C's. At most I'd say you could get one A at the cost of other subjects, but definitely don't do that.
I'd say don't work with a specific grade in mind, just try and cover the whole spec as best you can for all subjects and see what happens. I don't think there's much more you can do at this stage really, working to get a specific (very high) grade would just burn you out.