What is the theme of Chains by Laurie Halse Anderson?

If you've read the book, which I hope you have, there are a lot of conflicts. Not just one. There's the conflict between Kate and Teri--Kate and Teri have never been friends (it is suggested that Teri used to bully Kate) but eventually Kate wants to help Teri once she gets to know her. Then there's the conflict of Kate and MIT, and Kate not knowing what to do when MIT rejects her. There's conflict between Kate and her boyfriend Mitchell (they don't know where their life/relationship is going) and there's also a little conflict between Kate and her dad (ex science vs. religion).