Correct answer: Qd6-d3 1.Qd6-d3 ! zugzwang. 1...Kd1-e1 2.Qd3*e2 # 1...Kd1-c1 2.Qd3*c2 # 1...c2-c1=Q 2.Qd3*e2 # 1...c2-c1=N