Correct answer: Nb31...Kc4[a] 2.Bd3#[A] 1...Kc6/[б]/ 2.Bd7#[Б] 1.Ka7? zz 1...Kc4[a] 2.Bd3#[A] 1...Kc6/[б]/ 2.Bd7#[Б] but 1...d4! 1.Kb8? zz 1...K