QUOTE
you can use any version of the music you play for an exam unless a specific arrangment of the music is needed
Be careful you dont' confuse "edition" and "arrangement".
They are not one and the same thing.
You can use any edition, unless one edition is specified.
An arrangement may mean the original is simplified and may in fact have some of the notes missing. Different editions are less likely to have interfered with the actual notes of the piece, but may have less fundamental differences in eg expression marks, phrasing, dynamics added, and that sort of thing.
You can't actually use any
version of a piece, for instance some versions of Fur Elise have the whole middle section missing.
Crazy Purple Piano Freak, your edition of the Debussy Arabesque may be ok but I'd want to check it with a standard edition to make sure it's not altered or simplified in some way.