#1 I would not cheat and change the grades since this is unethical, and this may leave you with guilt and depression.
#2 You would take it to the lost and found since this is the ethical thing to do, as well as the safest way to handle this situation.
#3 I would not plagiarize since this is not my work, and because it is not my work, I can get into major trouble if I do plagiarize, like suspension or even expulsion.
