Cylindrical Capacitors: an Air-Filled Capacitor Is Formed from Two Long

Cylindrical capacitors: An air-filled capacitor is formed from two long conducting cylindrical shells that are coaxial and have radii of and The electric potential of the inner conductor with respect to the outer conductor is (k = 1/4πε₀ = 8.99 × 10⁹ N ∙ m²/C²) The energy stored in a 1.0-m length of this capacitor is closest to

A) 8.0 μJ.
B) 5.7 μJ.
C) 11 μJ.
D) 16 μJ.
E) 22 μJ.