waha1ha1

C knows the answer by deducing D is not yelling out the answer.tvb now,tvbnow,bttvb5 p# |9 }4 l2 N
That means D is not sure the answer by seeing one white and one black.
( Q$ m4 l* y  R, V, ^8 ^公仔箱論壇C saw B is wearing the white, hence he is wearing the black