Which of the following statements is correct about propagation rules?
A.
In the MF/HF band, Iow frequency is selected for long distance communication.
B.
The frequency selected during nighttime is lower than that selected during the daytime if the receiver is the same one.
C.
In the MF/HF band, the frequency selection bas nothing to do with the communication distance.
D.
The frequency selected during daytime is lower than that selected during the night time if the receiver is the same one.