\textbf{196-} The electric field function of an electromagnetic wave in SI is $E = E_{\max}\sin 2\pi\!\left(10^8\,t - \dfrac{x}{3}\right)$. This wave is in the ........... range.
(1) Gamma rays \hfill (2) Violet \hfill (3) Radio waves \hfill (4) Infrared