Physics · Electrostatic Potential

Consider the following statements regarding electrostatic potential: (A) Electrostatic potential at a point is equal to the work done by an external force in bringing a unit positive charge from infinity to that point without acceleration. (B) The unit of electrostatic potential is Joule per Coulomb (\( \text{J C}^{-1} \)) or Volt. (C) Electrostatic potential depends on the magnitude of the test charge \( q \) used to define it. (D) Potential at any point due to a positive charge is positive, and due to a negative charge is negative. Which of the above statements are correct?

1. A
   (A) and (C) only
2. B
   (A), (B) and (D) only
3. C
   (B), (C) and (D) only
4. D
   (A), (B), (C) and (D)