G1E10 : Why should an amateur operator normally avoid transmitting on 14.100, 18.110, 21.150, 24.930 and 28.200 MHz?

A A system of propagation beacon stations operates on those frequencies

B A system of automatic digital stations operates on those frequencies

C These frequencies are set aside for emergency operations

D These frequencies are set aside for bulletins from the FCC

Correct Answer: A system of propagation beacon stations operates on those frequencies