both of these work for me, even though that’s not the case for everybody :)
i feel like rewriting notes helps you refresh your memory (you know, about what you’ve learned in class) and reviewing a friend’s notes provides a sense of familiarity (as weird as it may sound hehe). so in my defense, the answer would be C. hope that clears it up (or at least, makes it a little less confusing haha), have a nice day! x