C knows the answer by deducing D is not yelling out the answer.
0 L. r, g5 ~# L" d, M6 v' Q7 OThat means D is not sure the answer by seeing one white and one black.tvb now,tvbnow,bttvb7 l; j# p# L& I3 [7 r
C saw B is wearing the white, hence he is wearing the black |