In frequency modulation
A. Frequency of `CW` remains constant but amplitude changes in accoradance with modulating wave frequency
B. Frequency of `CW` changes in accordance with the modulating wave frequency but the amplitude also changes.
C. Frequency of `CW` changes in accordance with the modulating wave frequency but the amplitude remains constant.
D. Frequency of `CW` changes in accordance with the amplitude of modulating wave amplitude