Correct answer: Qb51...c4 2.Q:a7# 1...e4 2.Q:g7# 1.Qf5? (2.Qd3#) 1...c4 2.Ne2# (A) 1...e4 2.Q:d5#(B) but 1...Nb2! 1.Qb5! (2.Qd3#) 1...c4 2.Q:d5#