C knows the answer by deducing D is not yelling out the answer.5.39.217.77:8898, B3 o7 V; Z/ M7 J6 k- J1 t
That means D is not sure the answer by seeing one white and one black. " X% c9 p+ L* K! T9 M7 H* Jtvb now,tvbnow,bttvbC saw B is wearing the white, hence he is wearing the black
C, because he saw B's hat is white and he knows D can see the color of B's and his hat. If B and his hat has the same color, D would speak out. But D kept silent, so C knows that his hat's color must be different.