Which are the popular IF frequencies for microwave and radar receivers operating on frequencies in the range 1 to 10 GHz

A)
3, 6 and 7 kHz
B)
3, 6 and 7 GHz
C)
30, 60 and 70 kHz
D)
30, 60 and 70 MHz

Correct Answer : Option (D) :   30, 60 and 70 MHz