The statement that is true about a story's narrator is:
The narrator controls what information the reader receives about the plot, characters, setting, and conflict.
This reflects the role of the narrator in shaping the reader's understanding of the story by providing or withholding information as needed. The other statements are not universally true. The narrator is not always the author, may not know everything about all characters, and does not necessarily have to be a character in the story. Additionally, some narrators do have limited perspectives based on a particular character's experiences, but this only applies in certain narrative styles, such as first-person narration.