In the figure below, four charges are arranged at the corners of a square. The potential Vis zero at which of the points marked by black circles? D + Q - - - + Q - - - - - . A - - B C 0- - - - - - - - - ---- - - E 1 Q - Q B, D and E B only A, C, D and E A and C only A, B, C, D and E V is not zero at any of these points D and E only A, B and C