Physics · Electrostatic Potential

Consider the following statements regarding electrostatic potential: (I) Potential at a point due to a point charge \( Q \) is inversely proportional to distance \( r \). (II) For a negative charge, potential is negative. (III) Electrostatic potential is a vector quantity. (IV) The unit of electrostatic potential is joule per coulomb. How many of the above statements are correct?

1. Only one
2. Only two
3. Only three
4. All four