Correct answer: Qb21...Nd5[a] 2.R:d5#[A] 1...Nc6/[б]/ 2.R:c6#[Б] 1...Nb6[c] 2.Ne6#[C] 1...Bd4[d] 2.Nd7#[D] 1...Nf5/Ng8/Nc8 2.Rd5#[A]/Rc6#[Б] 1...B