Black's King can't move without placing himself in check and the pawn's progression is blocked by the bishop.
Incorrect Chess Stalemate

It is a stalemate:
Ka4-rook
Ka6-bishop
Kb5-pawn,bishop, queen
Kb6 and Kb4-queen
pawn is blocked by bishop.
Result-stalemate.

Perhaps a better question is, why would you let this happen? I saw at least 3 mate in 1 or 2s. Why not play any of those?
How is this a stalemate?