C knows the answer by deducing D is not yelling out the answer.2 M6 t1 o- S- Z i1 @
That means D is not sure the answer by seeing one white and one black.www2.tvboxnow.com5 g& s/ F) o* s' @! j
C 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.