Correct answer: Qa21...Kb1 2.O-O# 1...d:e2 2.K:e2# 1.Rg1?? zz 1...d:e2 2.K:e2# but 1...Kb1! 1.Rf1?? zz 1...d:e2 2.K:e2# but 1...Kb1! 1.e:d3?? (2.Ke2#) but
