I just didn't capitalize the first "Ο", and my whole correct answer was marked wrong.... Unfair!
It's fixed now. For some reason, the O in the correct answer was the latin one and not the greek one, making the Greek keyboard Ο incorrect... :)
Καλησπέρα. Θεώρησε λανθασμένη την απάντηση «ο καπνός γυρίζει πίσω», γιατί;