Three people A, B, C are standing in a line in such a way that C can see both A and B. B can see only A, and A can see none of them. They are shown 5 hats, 2 of which are black and 3 of which are white. After this, they are blindfolded and a hat is placed on each of their heads and the blindfolds are removed. None of them can see his own hat. When C is asked regarding the colour of the hat he is wearing, he is unable to answer. Then B is asked and he too is unable to answer but finally A is asked the same question and he gives the colour of his hat. What is the colour of the hat on A’s head?