Two point charges of and  are located at both sides of an infinite and grounded conductor plane, and the distance between the charge and the plane is . Let the potential  at the region of  and the potential  at the region of . Which statement as follows is right?
A、, where  is the distance between the field point and .
B、, where  is the distance between the field point and , and  is the distance between the field point and the image of .
C、, where  is the distance between the field point and , and  is the distance between the field point and .
D、, where  is the distance between the field point and , and  is the distance between the field point and the image of .