White can take the Knight with check
Taking with the Queen is also possible
Black would exchange Queens
And after White takes back
Black would move the King aside
The position without Queens favors Black
Since there will be no checkmate threats
So, taking with the Bishop is better
Black is forced to move the King either here
Or here
Moving it to this square is bad
White would give a check here
And when Black moves the King
This will be checkmate