Three waves A,B and C of frequencies $1600\;kHz, 5 MHz$ and $60\;MHz$ respectively are to be transmitted from one place to another . Which of the following is the most appropriate mode of communication ?

Question

$\begin{array}{1 1} \text{A is transmitted via space , while B and C are transmitted via sky wave } \\\text{A is transmitted via ground wave , B via sky wave and C via space wave} \\ \text{B and C are transmitted via ground wave while A is transmitted via sky wave } \\ \text{B is transmitted via ground wave, while A and C are transmitted via space wave } \end{array} $