An electromagnetic wave in vacuum has the electric and magnetic fields $\overrightarrow{E}$ and $\overrightarrow{B}$, which are always perpendicular to each other. The direction of polarization is given by $\overrightarrow{X}$ and that of wave propagation by $\overrightarrow{k}$. Then :

Question

( A ) $\overrightarrow{X} || \overrightarrow{E}$ and $\overrightarrow{k} || \overrightarrow{E} \times \overrightarrow{B}$
( B ) $\overrightarrow{X} || \overrightarrow{B}$ and $\overrightarrow{k} || \overrightarrow{E} \times \overrightarrow{B}$
( C ) $\overrightarrow{X} || \overrightarrow{B}$ and $\overrightarrow{k} || \overrightarrow{B} \times \overrightarrow{E}$
( D ) $\overrightarrow{X} || \overrightarrow{E}$ and $\overrightarrow{k} || \overrightarrow{B} \times \overrightarrow{E}$