The statement that most accurately analyzes how the author’s choices in using juxtaposition define the narrator’s perspective is:
"The narrator’s feelings of pity and amusement at the old man’s fear emphasize the narrator’s morbid state of mind."
This choice highlights the contrasting emotions the narrator experiences, showcasing a complex psychological state that reveals both a lack of empathy and an unsettling enjoyment derived from another’s fear, thus defining the narrator's disturbed and morbidly twisted perspective.