That the choice is with the drop-out, provided educational establishments were willing to let them back. But if the drop-out insists it is, "for good", it means they presently have no intention of ever going back.
There might be differences here between British and US usage. Brits generally only use the word 'school' to refer to compulsory education, so one can't (legally) 'drop out' of school. Americans seem to use the word 'school' to embrace post-compulsory education as well, so it's possible for them to 'drop out of' (= 'finish with') school.
Smeydiss. You've asked six questions and received many useful answers from several ABers, yet you haven't had the courtesy to thank anyone. Remember you are communicating with real people on here not a computerised answering machine.
Making an answer to your own question(s), like you have, is how you reply - if your reply is to one person then put their username at the start of your reply. I hope you mean goodbye "for now" and not "forever".