A spherical cavity is hollowed out of a conductive sphere of radius b. The conductive sphere is surrounded by two concentric dielectric spherical shells with radii c and d and permitivities 1 and 2 respectively. At the center of the cavity, we have a point charge q. (see figure below) (a) what is the voltage of this sphere assuming zero voltage at infinity? (13 pts) (b) what is the bound volumteric and surface charge densities? (6 pts) (c) what is the surface charge densities on the conductor sphere and cavity. (6 pts)