C knows the answer by deducing D is not yelling out the answer. 9 a2 U2 ?8 P, \& V& g6 O( Gtvb now,tvbnow,bttvbThat means D is not sure the answer by seeing one white and one black. 0 ~9 z# k& f w; z# s3 RC 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.