A metal sphere has a net electrical charge of +40 nC. What can we say about the magnitude of the E-field inside the sphere?

a. It is a constant value at all points inside the sphere.

b. It is zero at the center of the sphere and increases as you move towards the edge of the sphere.

c. It is zero at all points inside the sphere.

d. It is zero on the surface of the sphere and increases as you move towards the center.