Correct answer: Nf11...Kd3/d5 2.Qc3# 1.Kf3?? zz 1...Kd3/d5 2.Qc3# but 1...Ke5! 1.Kf5?? zz 1...Kd3/d5 2.Qc3# but 1...Ke3! 1.Kg5?? zz 1...