Correct answer: Nd51...c5 2.Qb5# 1.Na2?? zz 1...Ka4 2.Qb4# 1...c5 2.Qb5# but 1...K:a6! 1.Qb7?? zz 1...c5 2.Qb5# but 1...a2! 1.Bc4?? zz 1...c5 2.Q