Which of the following results regarding electrostatics of conductors is not true?

• A. At the surface of a charged conductor, electrostatic field must be tangential to the surface at every point.
• B. Inside a conductor, electrostatic field is zero.
• C. The interior of a conductor can have no excess charge in the static situation.
• D. Electrostatic potential is constant throughout the volume of the conductor and has the same value (as inside) on its surface.