A spherical shell of radius R has a charge Q uniformly distributed on its surface. What is the force exerted by one half over the other.

Question

$(A)\;\frac{Q^2}{4 \pi \in _0 R^2}\\ (B)\;\frac{Q^2}{4 \pi \in _0 R^2}\times 2 \\ (C)\; \frac{Q^2}{16 \pi \in _0 R^2} \\ (D)\;\frac{Q^2}{32 \pi \in _0 R^2}$