6. Choose the INCORRECT statement:
(A) Gauss's law holds in a vacuum
(B) Gauss's law states that the net number of lines crossing any closed surface in an outward direction is proportional to the net charge enclosed within the surface
(C) Coulomb's law can be derived from Gauss's law and symmetry
(D) Gauss's law applies to a closed surface of any shape
(E) according to Gauss's law, if a closed surface encloses no charge, then the electric field must vanish everywhere on the Gaussian surface.