I believe that your correct answer would be "pacing".
The reason why I say that "pacing" would be your correct answer is because the word "pacing" allow for the author to pull event's and drag them in the story for the story to have more of a story. Your answer would NOT be "flashback" because a "flashback" is when the author identifies the past tense of the story. The option "foreshadowing" would NOT be your answer because "foreshadowing" is something that would happen in the future that the author is explaining. Your answer would NOT be "conflict" because a "conflict" is a problem that is arousing. There is no problem that is arousing. Your CORRECT answer would be "Pacing".