Correct answer: B:c71...R:f4 2.N:f4# 1...Rfe7 2.Nf6# 1...Be7 2.N:c7# 1.N:c7+?? 1...B:c7 2.B:b7# but 1...R:c7! 1.f5?? (2.Nf4#/Qd2#) 1...B<