A plane electro magnetic wave is propagating through space consider unit area perpendicular to the direction of propagation. If $\overrightarrow{E}\text{\hspace{0.17em}and\hspace{0.17em}}\overrightarrow{B}$ are instantaneous electric and magnetic field components then instantaneous rate of energy flow through the unit area is given by 

• A

  $\frac{1}{{\mu }_0}|\overrightarrow{E}\times \overrightarrow{B}|$

• B

  $\frac{1}{{\in }_0}|\overrightarrow{E}\times \overrightarrow{B}|$

• C

  $\frac{1}{2}{\in }_0|\overrightarrow{E}\times \overrightarrow{B}|$

• D

  $\frac{1}{2{\in }_0}|\overrightarrow{E}\times \overrightarrow{B}|$