C knows the answer by deducing D is not yelling out the answer.
/ u2 k0 V+ X+ `9 o$ a0 x+ c; Xtvb now,tvbnow,bttvbThat means D is not sure the answer by seeing one white and one black.
1 A* B8 I4 [ R, p, |tvb now,tvbnow,bttvbC saw B is wearing the white, hence he is wearing the black |