My first thought on reading about an 11yo doing AP science in a flipped class is: asynchrony. Learning is not difficult for a gifted child, but learning how to learn is a different animal. It's easy for you to say what's important, for example, because you're already educated on the subject, but your DD can't figure it out on her own. So, B.

Your DD's feedback should be strongly considered, so that makes two of us for B.