Correct answer: Bf51.Bg4?? zz 1...Kb3 2.Bd1# but 1...Kd3! 1.Bc6?? zz 1...Kd3 2.O-O-O# but 1...Kb3! 1.Rc4+?? 1...Kb3 2.Rc3# but 1...Kd3! 1
