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?
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.”