During rainy or cold winter weather, how should the bus driver operate the vehicle ventilation/defrosting system (除霜除雾系统) to eliminate windshield condensation rapidly?

1. Turn on the front windshield defroster (A/C dehumidification mode) with external air intake, directing dry warm/cool airflow across the inner glass surface
2. Wipe the windshield vigorously with a dirty towel while driving at 80 km/h
3. Turn off all blowers and close all cabin vents completely
4. Spray soapy water onto the exterior windshield while in motion