The correct answer is:
Al Jolson's movie The Jazz Singer was important culturally because its release declared the commercial rise of sound films and concluded the silent film era.
The Jazz Singer is a 1927 American musical film, directed by Alan Crosland and produced by Warner Bros. It was the first feature-length motion picture with not only a synchronized recorded music score, but also lip-synchronous singing and speech, with its Vitaphone sound-on-disc system.