The correct answer is: B) How she has to conform to express her individuality.
Our individuality is the thing that makes us different from anyone else, in this case the narrator can't express it in a complete manner as she has to follow the rules imposed by a catholic school. She identifies with the hippie style and loud music, but attending a catholic school makes it impossible to her to express that part of her personality. Her parents seem to have different cultural norms as they enrolled her in that school. She doesn't seem to have the interest in adapting to their way of thinking, by having an "unspoken agreement" she can be herself when she is not attending classes. We can say that she is able to fit in school by being a "good Catholic girl" and although she can express her feelings at her home her parents don't really seem to accept her, so she hasn't been able to addapt completely.