Physics · Electrostatic Potential

A charge \( q \) is brought from infinity to a point \( \mathbf{r} \) in an external electrostatic potential \( V(\mathbf{r}) \). The electrostatic potential energy of the charge in this external field is given by:

1. A
   \( -q \, \nabla V(\mathbf{r}) \)
2. B
   \( \frac{V(\mathbf{r})}{q} \)
3. C
   \( \frac{1}{2} q \, V(\mathbf{r}) \)
4. D
   \( q \, V(\mathbf{r}) \)