If electric permittivity and magnetic permeability of the medium are respectively $$\varepsilon $$ and $$\mu $$, then the velocity (C_m) of the electromagnetic wave in the medium is given by:

A. $${{\text{C}}_{\text{m}}} = \frac{1}{{\varepsilon \mu }}$$

B. $${{\text{C}}_{\text{m}}} = \frac{1}{{\sqrt 8 \mu }}$$

C. $${{\text{C}}_{\text{m}}} = \frac{5}{{\sqrt \varepsilon \mu }}$$

D. None of these

Answer: Option B