Lines of Charge: Two Long Conducting Cylindrical Shells Are Coaxial

Lines of charge: 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? (k = 1/4πε₀ = 8.99 × 10⁹ N ∙ m²/C²)

A) 10,000 V/m
B) 14,000 V/m
C) 18,000 V/m
D) 22,000 V/m
E) 26,000 V/m