Suppose that the electric field part of an electromagnetic wave in vaccum is $E= 3.1 \times N/c$ an $[(1/8 rad/m)y +(5.4 \times 10^8\;rad/s/t)$ what is the amplitude of the magnetic field part of the wave ?

Question

$\begin{array}{1 1} 1.03 \times 10^{-8}\;T \\ 10.3 \times 10^{-8}\;T \\ 10.3 \times 10^{-6}\;T \\ 1.03 \times 10^{-8}\;T \end{array}$