Correct answer: Nb11...Kc4 2.d5# 1.Nd5+?? 1...Ka4 2.B:d7#/d:c5# 1...Kc4 2.d:c5#/R:c5# but 1...R:d5! 1.Nb1! zz 1...Ka4 2.d:c5# 1...Kc4 2.d5# 1..