A radio can tune any station in the $7.5 \;MHz$ to $12\;MHz$ band . What is the corresponding wave length band ?

Question

$\begin{array}{1 1} 45\;m - 25\;m \\ 40\;m - 20\;m \\ 40\;m - 25\;m \\ 40\;m - 30\;m \end{array} $