Black and white hats

There are 3 black hats and 2 white hats in a box. Three men (we will call them A, B, & C) each reach into the box and place one of the hats on his own head. They cannot see what color hat they have chosen. The men are situated in a way that A can see the hats on B & C's heads, B can only see the hat on C's head and C cannot see any hats.

When A is asked if he knows the color of the hat he is wearing, he says no.

When B is asked if he knows the color of the hat he is wearing he says no.

When C is asked if he knows the color of the hat he is wearing he says yes and he is correct.

What color hat and how can this be? There is no play on words and there are no tricks. If had is used instead of has it is purely accidental

asusual answers in the comment section...