How does Article 133 of Bahrain's Traffic Law Implementing Regulation state the legal standard for a vehicle's tyres?

1. As a fixed minimum tread depth in millimetres
2. As a condition and suitability test: pneumatic rubber tyres in good condition that do not allow the vehicle to skid, matched to the vehicle's design, axles and rims, not protruding beyond the body, firmly fixed, and able to bear the vehicle's maximum weight
3. As a requirement to replace tyres every 20,000 kilometres
4. As a rule that applies only to commercial vehicles