Two electric charges, $$+q$$ at the origin $$O\,(0,0)$$ and $$-2q$$ at the point $$A\,(6,0)$$, are placed on the $$x$$ axis. The locus of the point $$P$$ in the $$x-y$$ plane where the potential vanishes, $$V = 0$$, is

A

a straight line perpendicular to $$x$$ axis and passing through $$(2,0)$$

B

only the point $$(2,0)$$

C

a circle with center at $$(-2,0)$$ and radius $$4$$

D

an ellipse with foci at $$O$$ and $$A$$