In this sentence, should I use the or a?
Mom: I think making a copy of this picture would be a good idea since your aunt wants a copy.
Me: Sure, I can make the copy.
Should I say "a copy" in order to make sense? Do I need to say "a copy" first and say "the copy" later in the conversation when referring to that copy? I'm not sure how early into the conversation I can start using the instead of a.