The correct answer is B) was an immediate success.
In 1920, America's first radio station was an immediate success.
We are talking about the radio station called KDKA in the city of Pittsburgh, Pennsylvania. This station was inaugurated on November 2, 1920. The first transmission of this date was the results of the Presidential elections. American people were excited that the radio could transmit messages in real-time and they could know about the news before the newspaper was printed. That is why the radio was a total success in the US.