None of the above. It's not "OK", but the stern talk won't work either. Rather, try to get to the bottom of it: why aren't they trying? Don't they think it's worth it? How would they like to make a living? Are they so overwhelmed by something else that they stopped caring about their future...?
@gfantasy That is how my dad and his girlfriend are. They shut me up quickly when I tried to make excuses. His girlfriend called me out and got blunt with me that I must don’t care about my grades and family will be disappointed if they find out I won’t be graduating.
@LaylaTheTallGirl I get it, I don't think their approach works, yet this is about you, not about them. It's about your future. You want to graduate because of you, not because your family wants or demands you to. What are your thoughts about it? What subjects make you struggle the most...?