The electric field and magnetic field components of an electromagnetic wave going through vacuum is described by:
$E_x = E_0 \sin (kz - \omega t)$$B_y = B_0 \sin (kz - \omega t)$Then the correct relation between $E_0$ and $B_0$ is given by:
$E_0 B_0 = \omega k$
$k E_0 = \omega B_0$
$E_0 = k B_0$