Correct answer: Nc41...f3[a] 2.N:e3#[A] 1...N:d4/[б]/ 2.R:d4#[C] 1...Nd6[c]/Ne7[c]/Nb6[c]/Na7[c] 2.Ne7#[D] 1...Nf8/Ng5/Ng7/Nd8/Nc5/Nc7 2.Re