Two identical charged spheres are suspended by strings of equal lengths. The strings make an angle of 30° with each other. When suspended in a liquid of density 0.8 g cm-3, the angle remains the same. If density of the material of the sphere is 1.6 g cm-3 then dielectric constant of the liquid is
(a) 4
(b) 3
(c) 2
(d) 1
