Final answer:
In frequency division multiplexing, the medium must support the sum of all individual frequency ranges, ensuring that the total bandwidth accommodates each channel plus guard bands to prevent interference.
Step-by-step explanation:
In frequency division multiplexing (FDM), the medium must be capable of carrying a range of frequencies that can support the sum of all the individual frequency ranges. This means that the total bandwidth of the medium must be equal to or greater than the sum of the bandwidths required for each channel.
In FDM, each channel is allocated a unique frequency band within the overall bandwidth, and these bands must be separated by a guard band to avoid interference, which also contributes to the total bandwidth requirement.
In frequency division multiplexing, the medium must be capable of carrying a range of frequencies that can support the sum of all the individual frequency ranges.
For example, in frequency modulation (FM) for radio transmission, different audio signals are combined and transmitted by varying the frequency of a carrier wave. The carrier wave must have a bandwidth that can accommodate the sum of the frequencies of all the audio signals.
Therefore answer is b. sum.