Two isolated charged conducting spheres of radii a and b produce the same electric field near their surfaces . The ratio of electric potential on their surfaces is

Question

$(a)\;\large\frac{a}{b}\qquad(b)\;\large\frac{b}{a}\qquad(c)\;\large\frac{a^2}{b^2}\qquad(d)\;\large\frac{b^2}{a^2}$