The correct answer is: Option D. They create a matter-of-fact tone.
A matter-of-fact tone is described as a strict, not imaginative, and dry expression of an author's conveyance of feelings in their words which focuses primarily on presenting facts.
By establishing a specific date, time, and place, the author applies a strict tone to their work with the intent of giving it non-fictional value - which means the author tries to convince the reader that the story can be compared to reality.
