During heavy rainfall with 50 passengers on board, the saloon windows begin to fog up rapidly. What is the most effective HVAC configuration to restore clear visibility?

1. Set the HVAC system to 100% air recirculation and turn off the A/C compressor
2. Set the HVAC system to fresh-air mode (Außenluft), activate the air conditioning compressor to dehumidify incoming air, and direct airflow to the windshield and side glazing
3. Open all roof hatches fully while maintaining maximum heater blower speed
4. Turn off the cabin heating system and instruct all passengers to close their window curtains