Correct answer: Kf21...K:g1 2.O-O-O# 1...Ng6/Nh5/Ne2/Ne6/Nd5 2.Q:h2# 1.Q:f4?? (2.Q:h2#) but 1...g:f4! 1.Ra2?? zz 1...Ng6/Nh5/Ne2/Ne6/
