Answer this question for the reading passage Secret in Slovakia. Which sentence from the passage's resolution best explains the surprising realization about Aunt Gertrude?
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A. “I had never asked my mother or uncle what they thought we might discover at Aunt Gertrude’s house, because I was certain that they would not know.”

B. “Aunt Gertrude had used [the money] to open a school for orphan girls in the city where she had grown up.”

C. “On the top was stationery that looked as if it were about 50 years old; the letterhead had a picture of a building with the words ‘Bratislava School for Girls.’”

D. “In the letter, she explained that she had been bequeathed a large sum of money when she was a young woman by one of the families for whom she had worked.”