What detail most clearly belongs to conclusion of the monkeys paw?

The detail that most clearly belongs to the conclusion of "The Monkey's Paw" is the return of Mr. White's son Herbert as a mangled and horrifying corpse.

Here's why:

* It resolves the central conflict: The entire story revolves around the Whites' wish for wealth, which ultimately brings about Herbert's death. This detail signifies the tragic consequences of their wish and the fulfillment of the paw's curse.

* It creates a sense of closure: The return of Herbert's body serves as a chilling and conclusive end to the story, leaving the reader with a lasting sense of dread and the understanding that the paw's power is absolute and destructive.

* It emphasizes the theme of unintended consequences: The return of Herbert's body as a corpse underscores the story's message about the dangers of tampering with fate and the potentially devastating consequences of unchecked desires.

While other details like the White family's fear and despair, the final wish made by Mr. White, and the disappearance of the monkey's paw itself contribute to the conclusion, the return of Herbert's body is the most definitive and impactful element that signifies the story's tragic end.