Answer:
The excerpt that best reveals the allegorical nature is: Option D: With a shuddering impulse, that showed her a woman still, the widow clasped her skinny hands before her face, and wished that the coffin-lid were over it, since it could be no longer beautiful.
Explanation:
We say that allegory is used in a story when the author uses the characters and settings as symbols which have a deeper meaning and not the obvious meaning of the story. It is used to explain the moral principles in one's life. and the universal truths.
"Dr. Heidegger's Experiment" by Nathaniel Hawthorne is a story that uses allegory beautifully.
Option D shows allegory as it explains that the body is no longer youthful and an old body cannot return to a youthful one. Time passes by and the youthfulness which the four people gained was momentarily.