What specific feature on an AP controls how much of the spectrum is available to transfer data? a. channel width b. channel selection c. channel frequency limit d. channel variance

a. channel width

Explanation:

In wifi, channel width defines how broad the spectrum is available to transfer data. A good example is, when using 5GHz it is usually recommended to use 40MHz as channel width, If you use 2Ghz,  you are recommended to use 20Mhz as channel width, because 20MHz is supported by older devices.

Basically, channel width defines the broadness of a wifi signal.