Question

Why did totalitarian governments control culture, such as books and films?

to ensure that all citizens had access to the arts
to support writers, directors, and other artists
to prevent culture from playing any role in society
to make sure that all culture followed state ideology

Answer 1

To make sure that all culture followed state ideology.

Totalitarian regimes tightly controlled books, films, art, etc., to use culture as propaganda, indoctrinate citizens, and suppress dissenting or independent viewpoints.