Correct answer: Bb51.Ne3+?? 1...Kd4 2.Bb2# but 1...Kd6! 1.Nb6+?? 1...Kd4 2.Bb2# but 1...Kd6! 1.Nc6+?? 1...Kb5 2.Nb6# but 1...Kc4!
