FM detectors are also referred to as discriminators because they discriminate in terms of what?

FM detectors are referred to as discriminators because they specifically discriminate based on frequency. The primary function of an FM detector is to extract the original information signal from the modulated carrier wave by distinguishing between different frequency deviations of the received signal.

When a frequency-modulated signal is transmitted, the information is encoded in the frequency variations of the carrier. The FM detector detects these changes in frequency and converts them back into the corresponding amplitude variations of the original signal, essentially discriminating which frequency deviation corresponds to which signal information. This process allows the FM detector to effectively recover the transmitted audio or data signal contained within the frequency-modulated wave.

In this context, the other options may refer to different characteristics of signals, but they do not accurately convey the fundamental role of an FM detector in differentiating signals based on frequency deviations.