you didn't finish the sentence , how am i gonna you if you didn't finish the sentence
line a --> main
line b --> young
line c --> atitude
answer: "the beating heart symbolizes the narrator's conscience, or his sense of guilt and wrongdoing" so its b
"to look at him, or hear him describe it, he had no guilt. however, poe decided to symbolize this man's subconscious guilt through the heartbeat."