Two positive charges Q and 4Q are placed at points A and B respectively, where B is at a distance 'd' units to the right of A. The total electric potential due to these charges is minimum at P on the line through A and B, What is (are) the distance(*) of P from A?
(A) d/3 units to the right of A
(B) d/3 units to the left of A
(C) d/5 units to the right of A
(D) d units to the left of A
