Final answer:
Radio broadcasts of live and recorded music began to reach large audiences during the 1920s.
Step-by-step explanation:
The answer to the question is B. 1920s. Radio broadcasts of live and recorded music began to reach large audiences during the 1920s. The National Broadcasting Company (NBC) and the Columbia Broadcasting System (CBS) started running sponsored news programs, radio dramas, and comedy programs during this time. By the late 1930s, radio also included talk shows, religious shows, educational programs, game shows, and quiz shows. By 1940, almost 83 percent of households had a radio, demonstrating its widespread adoption.