Final answer:
Before the invention of phonofilm, early movie theaters used live musicians for sound, but mostly struggled with early attempts at synchronized soundtracks because of technical limitations, especially synchronization issues.
Step-by-step explanation:
Before the invention of phonofilm, movie theaters primarily used live musicians to provide music during screenings. This was the most common way of attempting to pair sound with the visuals of early films. Live musicians, despite being an important part of the film experience at the time, provided an inconsistent experience, as the performance could vary each time a film was shown.
The technique did not work very well due to technical limitations, specifically the lack of synchronization between the sound and the picture. Early attempts at synced soundtracks existed, using devices like the Vitaphone system, which involved playing a record in synchronization with the film. However, this system had difficulties in maintaining perfect sync throughout the screening.
The correct answer to the question is option b) They used early attempts at synchronized soundtracks. It didn't work well due to technical limitations.