Two identical charged spheres are suspended by strings of equal lengths. The strings make an angle of $30^{\circ}$ 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 $16\;g\; cm^{-3}$, the dielectric constant of the liquid is

Question

( A ) 2
( B ) 1
( C ) 4
( D ) 3