What is the primary function and statutory installation requirement for the conductive static grounding strip (导静电橡胶拖地带) installed on road tanker vehicles transporting flammable liquids?

1. It must maintain continuous physical contact with the road surface during transit to discharge accumulated electrostatic charges to ground, with an electrical resistance not exceeding 100 Ω
2. It serves as a decorative mud flap to keep the rear license plate clean during rainy weather
3. It generates frictional electrostatic sparks to burn off fuel fumes trailing behind the truck
4. It acts as a magnetic anchor that increases tire braking friction on wet ice