True or False: In FM communication systems, the amplitude of the RF carrier varies with both the amplitude and frequency of the modulation signal.

In FM (Frequency Modulation) communication systems, the key characteristic is that the frequency of the radio frequency (RF) carrier wave is varied in accordance with the amplitude and frequency of the modulation signal, but the amplitude of the carrier wave itself remains constant.

In FM, only the frequency of the carrier signal is altered to encode the information from the modulation signal, while the amplitude of the carrier, which is crucial in amplitude modulation systems, does not change. This characteristic is what keeps the signal less susceptible to noise and interference, as variations in amplitude can be caused by many forms of interference that do not affect frequency.

Therefore, the statement regarding the amplitude of the RF carrier varying with both the amplitude and frequency of the modulation signal is false, making the correct response 'False.'