Correct answer: 1. Rb51.Rb5! zz 1...K:d5 2.R:c5# 1...Nd3/Na4/Na6 2.Nf3#/Nf7# 1...N:d7 2.Nf7# 1...Ne4 2.Nf3#/Nf7#/B:e4# 1...N