Which is the most likely reason film companies expanded so quickly?
advances in radio technology audiences to trust new technology; therefore, audiences wanted to see more films produced.

widespread film distribution increased revenue and popularity; therefore, film companies expanded in order to produce and distribute more films.

the post wwi economic boom allowed businesses and corporations to invest in filmmaking, and film companies were able to produce more films.

film technology began advancing so rapidly in the early 1900’s that film companies had to quickly expand in order to keep up.

The answer is : Widespread film distribution increased revenue and popularity; therefore, film companies expanded in order to produce and distribute more films.

Films are not just arts. It also about business. Basically a successful film with impressive production can expect higher return of revenue because they have established an impression to their fans and movie goers about their quality of their movies and productions. Successful films normally has parts and sequences. Since film industries are also businesses they are struggling more to develop higher quality movies with unique and impressive storylines in the future.