A. B, C, and D have different results. A. B, and C made speculations about this. A said: "A won first place, B won second place", and B said " C is second, D is fourth "; C says," A is second and D is fourth ". The actual situation is that all three of them were half right. Which of the following is correct? ['A second, D fourth.', 'A first, C third.', 'B first, D third.', 'C first, D fourth.']