A solid spherical conductor has charge +Q and radius R. It is surrounded by a solid spherical shell with charge -Q, innerradius 2R, and outer radius 3R. Which of the following statements is true?

Options

A. The electric potential has a maximum magnitude at C and the electric field has a maximum magnitude at A.
B. The electric potential has a maximum magnitude at D and the electric field has a maximum magnitude at B.
C. The electric potential at A is zero and the electric field has a maximum magnitude at D.
D. Both the electric potential and electric field achieve a maximum magnitude at B.

Answer

D