Answer:
The author use a simile to describe the squeaky hinges in this sentence from the story because Option D: The comparison adds an air of mystery and eeriness to the tone of the story.
Explanation:
Simile is a figure of speech which compares two things using words 'like' or 'as'. In the given line the author uses the simile 'like a platoon of lost ghosts'.
Platoon is a small group of soldiers. He describes the squeaking of hinges like a platoon of lost ghosts. It makes the story mysterious and tone oft he story gets more eeriness, Option D.
He is not making the plot believable as per Option A. Also, as mentioned in Option B, he is not comparing hinges to something unfamiliar as we know what ghosts are. It doesn't give Sophie a chance to say something to his father, as per Option C.
