Maribell Had Always Done Well in Math and English

Maribell had always done well in math and English. But partway through her seventh-grade year, she stopped handing in math homework and spent more time talking during class than listening and working. Meanwhile, her grades in English have remained high. Which of the following is the most likely explanation for this behavior?

A) She no longer cares what her parents and peers think of her.
B) She has reduced expectations for success in math.
C) She is too busy to study.
D) She is building friendships with high-achieving peers.