Correct answer: c8N1.c8B?? zz 1...Kc6 2.Bb7#/Be4# but 1...Kc4! 1.a7?? zz 1...Kc6 2.a8Q#/a8B# but 1...Kc4! 1.c8N! zz 1...Kc4 2.Ncb6#
