a BIG yes... it makes no difference if you are living in U.S., Britain, or in Timbaktu. Getting into Oxford U. is one thing, but finishing off a degree is another tough accomplishment! Oxford University does not pander to excuses, whining, or bribes to make the professors there to change grades, once a grade on an exam is given out to the student! :-) If you do get in to Oxford U., your parents ought to be very proud of you.
Good luck...