The correct answer is B).
As the time passes Peter begins to open up to Anne and he becomes pleasant and attractive to her, by the end of their time in the Annexe, Peter changed in Anne's eyes because he has become more open and therefore earned her affection.
They were able to establish a mutual friendship because they lived in closed proximity and both longing for companionship. Although later on Anne realizes that the Peter she is infatuated with is merely a product of her wishful thinking projected onto him and distances herself from him.
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