When the author quotes the actress Sarah Brown as saying, I truly believe that this film gives an important message to audiences, the author is using A) repetition. B) a testimonial. C) an ethical appeal. D) the bandwagon method.

B) a testimonial ...

By quoting a famous person, the author is trying to convince readers that the movie is worth seeing by including a testimonial. The author hopes that people who like Sarah Brown will believe what she says about the movie, and that this will make people want to see the movie.