During the propagation of electromagnetic waves in a medium

Question

$\begin{array}{1 1}(A)\;\text{Electric energy density is equal to the magnetic energy density} \\ (B)\;\text{Both electric and magnetic energy densities are zero} \\(C)\;\text{Electric energy density is double of the magnetic energy density} \\(D)\;\text{Electric energy density is half of themagnetic energy density} \end{array}$