In a coaxial transmission line (ε_r = 1), the electric field intensity is given by:
$$E = \frac{{100}}{\rho }\cos \left( {{{10}^9}t - 6z} \right){u_p}{\text{V/m}}$$
The displacement current density is

A. $$ - \frac{{100}}{\rho }\sin \left( {{{10}^9}t - 6z} \right){u_p}{\text{A/}}{{\text{m}}^2}$$

B. $$\frac{{116}}{\rho }\sin \left( {{{10}^9}t - 6z} \right){u_p}{\text{A/}}{{\text{m}}^2}$$

C. $$ - \frac{{0.9}}{\rho }\sin \left( {{{10}^9}t - 6z} \right){u_p}{\text{A/}}{{\text{m}}^2}$$

D. $$ - \frac{{216}}{\rho }\cos \left( {{{10}^9}t - 6z} \right){u_p}{\text{A/}}{{\text{m}}^2}$$

Answer: Option C