Correct answer: d8N1.a8Q?? (2.Qa1#) but 1...Ba2! 1.b8Q?? (2.Q:b6#) but 1...Bb7! 1.c8Q?? (2.Qc3#/Be3#/Bc3#) 1...Bc4 2.Q:c4# but 1...Bc6!
