Answer:
A. Theater began to compete with movies and radio for popularity for the first time.
Step-by-step explanation:
Modern Drama is what the plays written in the 19th and 20th century are called, they were the first that started competing against Radio and Film for audience, we have to keep in mind that the early 20th century saw the rise of film and Radio, before this the only way of entertaining that wasn´t read was theater.