Correct answer: Nb51.Bb5? zz 1...Kb4[a] 2.Qd6#[A] 1...K:b6/[б]/ 2.Qd4#[Б] but 1...a4! 1.Kc7?? (2.Qd6#[A]) but 1...Kb4[a]! 1.Kb8?? zz 1...K:b6/[б]/ 2.
