Correct answer: Re21...Kc2 2.Nb4# 1...Nd2 2.Q:c3# 1...N:a3 2.O-O-O# 1.Nd4?? zz 1...Nd2 2.Q:c3# 1...N:a3 2.Rd1#/O-O-O# but 1...K:d4! 1.N:e7??
