The best central idea for the paragraph is how horror fiction uses suspense and the anticipation of danger to create tension, particularly when characters venture into threatening situations. The mention of Stephen King's work illustrates this, emphasizing that readers are aware of the risks characters face in horror settings, which heightens the overall suspense of the narrative. The focus is on the relationship between the reader's knowledge of the genre and the characters' actions in that context.
Your suggestion about familiar characters acting innocently does not directly align with the main focus of the paragraph, which is about the genre's structure and the use of suspense.