Two long conducting cylindrical shells are coaxial and have radii of 20 mm and 80 mm. the electric potential of the inner conductor, with respect to the outer conductor, is 600 v. what is the maximum electric field magnitude between the cylinders?

a. 26,000 v/m
b. 14,000 v/m
c. 10,000 v/m
d. 18,000 v/m
e. 22,000 v/m