Final answer:
The conflict between the narrator and the old man in 'The Tell-Tale Heart' is caused by the narrator's obsession with the old man's eye. The beating heart in the story represents the narrator's guilt and psychological torment. The narrator's point of view changes from paranoia to guilt and torment as the story progresses.
Step-by-step explanation:
2. PART A: In the story, the conflict between the narrator and the old man is caused by the narrator's obsession with the old man's eye, which he finds unsettling. The narrator's growing paranoia and fear of the eye fuels the conflict.
3. PART B: The quote that best supports the answer to Part A is: 'It is impossible to say how first the idea entered my brain; but once conceived, it haunted me day and night.' This quote shows that the narrator's obsession with the eye is the source of the conflict.
4. The beating heart throughout the story represents the guilt and psychological torment experienced by the narrator. It symbolizes the narrator's deteriorating mental state and his inability to escape the consequences of his actions.
5. At the beginning of the story, the narrator's point of view is filled with paranoia, fear, and obsession. However, by the end of the story, his point of view shifts to guilt, torment, and a confession of his crime. The possible cause behind these differences is the narrator's internal struggle and the weight of his guilt.