C knows the answer by deducing D is not yelling out the answer.
; Z9 E1 p' o9 |, {! g( \" y9 [www3.tvboxnow.comThat means D is not sure the answer by seeing one white and one black.7 q1 e7 [2 j, t) `& e% B4 |5 R
C saw B is wearing the white, hence he is wearing the black |