Correct answer: O-O-O1...Bb1 2.Ra5# 1...Ne7/Nb6/N:a7 2.R:d6# 1...Qf3/Q:g2 2.R:f5# 1.R:a2?? (2.Ra5#) 1...N:a7 2.R:d6# but 1...b:a2! 1.R<