The Rationale Behind Government Regulation of the Radio Industry Was

The rationale behind government regulation of the radio industry was based on the concept that

A) the electromagnetic spectrum is a public asset.
B) the Constitution did not have radio in mind, so radio is not covered by free-speech protections.
C) by making money radio became a business and therefore subject to government regulation.
D) radio waves were illegally being used by con-artists and hatemongers.