Choose the correct statements from the following:

(A) For a point charge, concentric spheres centred at the location of the charge are equipotential surfaces
(B) For practical purpose the earth is used as a reference at zero potential in electrical circuit
(C) In a cavity within a conductor without charges, the electric field is zero
(D) During charging by rubbing, the insulating material with higher work function becomes positively charged
(E) Dielectric polarisation means formation of electric dipole inside the dielectric

Choose the correct answer from the options given below:

(A), (B), (C) and (E)

 During charging by rubbing, the insulating material with lower work function becomes positively charged