The correct answer is "απειλητικά μηνύματα, κοροϊδευτικά μηνύματα, προσβλητικά μηνύματα, ενθαρρυντικά μηνύματα, ενεμερωτικά μηνύματα". The answer options provided are different types of messages that can be sent in the context of cyberbullying. These include threatening messages, mocking messages, offensive messages, encouraging messages, and informative messages.