The act that first emphasized that licensees did not own their channels but were granted licenses provided that they operated in the "public interest, convenience, or necessity" was the .

Radio Act 1927

Explanation:

Radio Act 1927 -

The act was the improved version of the Radio Act 1912 , which helps to increase the control of the federal government on the radio communications .

And a new entity known as the Federal Radio Commission was established .

It was the very first time that the station need to show " in the public interest, convenience, or necessity " , that would enable the radio stations to get proper license .

Hence , from the given information of the question ,

The correct answer is Radio Act 1927 .

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