Select the correct statement regarding the difference between the FM modulated signal waveform and the AM modulated signal waveform. a. The FM signal wave changes frequency according to the message wave m(t). The "peak" amplitude of the FM signal, Ac=5, remains constant. b. There is no difference between the FM and AM signal waves because they are both modulated by the same message wave, m(t) = Amcos(2fmt) c. The AM signal wave frequency changes with the message wave m(t) while the amplitude of the FM signal changes with m(t). d. All statements are correct.

AM modulation FM modulation 10 0 -5 -10 0 -5 0 0 time 10 tirne 10 combined message and FM signal combined message and AM signal -10 0 time 10 tirne 10