A force F acts between two charges kept 1 cm apart in air. If permittivity of air and dielectric constant of water are $\in _0$ and $K$ respectively, find the force acting when both atoms are placed in water.

Question

$(A)\;\frac{F}{K}\\ (B)\;\frac{F \in _0}{K} \\ (C)\; \frac{F}{K \in _0}\\ (D)\;\frac{FK}{\in _0}$