Fill in the blank (_) in the following sentence from the following choices.
Sentence: The libraries at the schools needed new books, but they couldn't get them because the _ were too expensive.

Choice 1: The libraries at the schools needed new books, but they couldn't get them because the schools were too expensive.
Choice 2: The libraries at the schools needed new books, but they couldn't get them because the books were too expensive.
Which of the choices is correct? Respond with only "1" or "2" and no additional text.
2
2.