Read the passage and answer the question.
PASSAGE (P21): Amina arrived at the library ten minutes before it opened. She stood near the door, re-reading the list of books she had written in her notebook. When the librarian unlocked the door, Amina walked straight to the history shelf and picked up two titles, then hurried to the counter. She smiled when she heard that both books were available to borrow.
QUESTION: Why did she smile at the counter?
Which option is the best inference from the passage?
Select the ONE best answer from the options panel.