A changed particle oscillates about its means equilibrium position with a frequency of $10^9$ Hz. The electromagnetic wave produced

Question

$\begin{array}{1 1} \text{will have frequency of } 10^9 Hz \\ \text{will have frequency of } 2 \times 10^9 Hz \\ \text{will have a wave length of } 0.3\;m \\ \text{fall in the region of radio waves} \end{array}$