I'm not sure if you are aware of this, but when AADSAS figures your GPA they will count both the original grade and the repeat. So as long as its not a prereq. I would say just take another class and get an A in it and the AADSAS GPA would be the same. As far as the schools I'm not sure how they look at it. Best bet is that if you have a certain school in mind you may want to call them and ask if it would help.