A parent at a designated stop is upset and wants to discuss a complaint about another student. The driver's route is on a tight schedule. How should the 7D driver handle this situation?

1. Engage in a detailed discussion with the parent at the stop to resolve the issue immediately.
2. Politely inform the parent that they cannot discuss the issue at the stop due to safety and schedule concerns, and advise them to contact the school or transportation office.
3. Tell the parent they are too busy and close the door.
4. Allow the parent to board the vehicle to discuss the matter privately while other students are present.