D is the correct answer :)
The person narrating has committed a murder and shoved the corpse under his floorboards. As some time passes the heart beat is a glimpse into his insanity, and how he is delusional over hearing non existent sounds. He believes he hears the heart of the person he murdered under the floorboards, which is a delusion, most likely made out of paranoia. When the police come to ask about the victim, the man almost fools them until he breaks down and confesses. He expressed annoyance at the victim earlier, saying that he could not get away from their eye, I believe. He tried to solve this by killing them, but his mind would not let him do so by making up false realities.
The main reason Harrison Bergeron is considered a threat in the eponymously titled short story is that he is able to rip off of his handicaps and make himself the self-proclaimed "Emperor," thereby removing control of the authoritarian regime that needs all of its citizens to weaken themselves and obey government commands.
Answer:
nation:
“An Encounter” suggests that although people yearn for escape and adventure, routine is inevitable, and new experiences, when they do come, can be profoundly disturbing. The narrator and his friends play games about the Wild West to disrupt the rote activity of school, and venture into Dublin for the same reason.