Under § 102 KFG and Austrian fire safety rules, what type of portable handheld fire extinguishers must be carried on an Austrian touring coach, and how should they be used on an incipient wheel-well/tire fire?

1. Water-only bucket; poured directly into the 24V electrical fuse box
2. Certified ABC dry powder or foam extinguishers (at least 6 kg capacity, inspected every 2 years); discharge in short, targeted bursts at the base of the flames from upwind, aiming into the wheel well
3. Carbon dioxide (CO2) extinguishers used exclusively to cool the driver's seat
4. No fire extinguishers are required on commercial buses in Austria