A cube of side b has a charge q at each of its vertices. Determine the potential and electric field due to this charge array at the center of the cube.
A. `(2q)/(sqrt(3) pi in_(0) b)` ,zero
B. `(4q)/(sqrt(3) pi in_(0) b)` ,zero
C. `(5q)/(sqrt(3) pi in_(0) b)` ,zero
D. `(7q)/(sqrt(3) pi in_(0) b)` ,zero