According to OHS regulations, if a driver discovers a small puddle of red, sweet-smelling liquid under the front of their parked vehicle, what is it likely to be, and what hazard does it present?

1. Engine coolant (ethylene glycol); it is highly toxic to ingest and indicates a cooling system leak
2. Automatic transmission fluid; it is highly acidic and will dissolve the concrete pavement
3. Windshield washer fluid; it poses an immediate fire explosion hazard
4. Engine oil; it indicates that the fuel tank is leaking gasoline