Under GB 13392-2005 and MOT vehicle safety regulations, what is the minimum standard provision for portable fire extinguishers on a dangerous goods transport truck?

1. At least two dry powder (ABC) fire extinguishers of adequate capacity (typically ≥ 4kg or 8kg each), securely mounted in quick-release brackets and within valid inspection dates
2. One small 500 mL domestic water spray bottle kept under the passenger seat
3. No fire extinguishers are required if the truck is equipped with an automatic cab air conditioner
4. A single bucket filled with wet garden soil