KxBishop - nothing stopping that, as tons of people have seen already, and then black queens one of the pawns - leading rapidly to checkmate. No stalemate! Especially not if the Bishop sits next to the black King!
Look at the position after KxB! What move does White's king have?
Right! None = Stalemate!!!
Especially not if you take the Bishop with Black's King - there will be no White's Bishop anymore to move!
Be sure at those puzzles, if they were not correct, there were many posts stating the puzzle is not correct. This puzzle is correct. Just take your time to study it.