Correct answer: B:b41...Kd1 2.Ra1# 1...d1B 2.Bf4# 1.Bf4?? zz 1...Kd1 2.Ra1# but 1...b3! 1.B:b4! zz 1...Kd1 2.Ra1# 1...d1Q/d1R 2.Ba
