No, I said where the parents were raised as children, not where the parents were born. If your parents were raised in France and are culturally French then you should play for France. It's always going to be an opinion anyway.
It seems to me that you should help the nation where your parents were raised as children. If there is then a choice between parents then let the player make that choice. I don't think your grandparents should be involved in any way. That would make a lot of the choices for players. If you don't...