Which of the following statements are correct ?
A. Inside a conductor, the electrostatic field is zero.
B. Electric field at the surface of a charged conductor does not depend on its surface charge density.
C. The interior of a charged conductor can have no excess charge in the static situation.
D. At the surface of a charged conductor, the electrostatic field must be normal to the surface at every point.
E. The electrostatic potential is zero everywhere inside a charged conductor.
Choose the correct answer from the options given below :

(C) A, C and D only
Statement A is correct because in electrostatics, the free charges inside a conductor redistribute themselves such that the net electric field inside is zero.
Statement B is incorrect because the electric field at the surface of a charged conductor is given by \(E=\frac{\sigma}{\epsilon_0}\), which directly depends on the surface charge density \(\sigma\).
Statement C is correct because, by Gauss's law, since the electric field inside the conductor is zero, the net charge enclosed by any Gaussian surface inside the conductor must be zero. Thus, any excess charge resides entirely on the outer surface.
Statement D is correct because if the electric field had a tangential component, free charges on the surface would experience a force and move, which contradicts the assumption of an electrostatic situation. Hence, the field must be normal to the surface.
Statement E is incorrect because the electric field inside a conductor is zero, which implies that the electrostatic potential is constant throughout the volume of the conductor, but it is not necessarily zero.
Therefore, only statements A, C, and D are correct.