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 (Where \[K=\frac{1}{4\pi {{\varepsilon }_{0}}}\]) [CBSE PMT 2003]

• A.   \[-K\frac{{{e}^{2}}}{{{r}^{3}}}\hat{r}\]        
• B.   \[K\frac{{{e}^{2}}}{{{r}^{3}}}\vec{r}\]
• C.   \[-K\frac{{{e}^{2}}}{{{r}^{3}}}\vec{r}\]       
• D.   \[K\frac{{{e}^{2}}}{{{r}^{2}}}\hat{r}\]