An electron is moving round the nucleus of a hydrogen atom in a circular orbit of radius r. The coulomb force $\overrightarrow{F}$ between the two is - <br> (where $K = \frac{1}{4 \pi \varepsilon_0}$ )

Question

( A ) $-K \frac{e^2}{r^3} \hat{r}$
( B ) $K \frac{e^2}{r^3} \overrightarrow{r}$
( C ) $-K \frac{e^2}{r^3} \overrightarrow{r}$
( D ) $K \frac{e^2}{r^2} \hat{r}$