Which of the following statement is NOT true?

The statement that is NOT true is identified as the correct answer in this scenario. Analyzing the options:

The first option references that the human voice produces analog signals, which is true. The sound waves created by human vocal cords are continuous waveforms that can vary in amplitude and frequency, representing analog signals.

The second option discusses the process of digitizing voice signals into a binary format for transmission, typically executed through modulation techniques. This is also accurate, as digitization allows voice data to be encoded into binary values, making it suitable for processing and communications over various media, including wireless.

The third option correctly states that FM stands for frequency modulation, a popular method used in radio broadcasting, wherein the frequency of the carrier wave is varied in accordance with the amplitude of the input signal.

Considering the accuracy of the first three statements, it confirms that option D, which claims that none of the other statements are untrue, is correct as a conclusion. Therefore, the identification of option D confirms that all other statements presented are indeed true, reinforcing the understanding of analog and digital voice signals and modulation techniques.