Final answer:
The correct answer is b. 1, as typically only one motor vehicle may be safely towed by a tow-bar due to safety and legal restrictions. Towing more than one vehicle could lead to control issues and increased accident risks.
Step-by-step explanation:
The question asks, "How many motor vehicles may be towed by a tow-bar?" The correct answer to this question is b. 1. When towing with a tow bar, it's important to ensure that the vehicle towing and the towed vehicle are properly equipped and aligned. Generally, a tow-bar allows one motor vehicle to be towed behind another motor vehicle. It's a physical link that ensures the towed vehicle follows the towing vehicle. The reason only one motor vehicle can be towed is due to safety concerns, control issues, and legal restrictions. Towing multiple vehicles, like in options a, c, or d, could lead to a lack of control, increasing the risk of accidents.
Towing regulations can differ by location, but the standard practice is to allow just one vehicle to be towed using a tow-bar. This setup requires a system of brakes and lights that are synchronized between the towing and towed vehicles, ensuring safety and communication on the road. Always consult local laws and vehicle specifications when setting up a vehicle for towing with a tow-bar.
Additionally, when towing a vehicle, drivers must consider factors like the Gross Combination Weight Rating (GCWR) of the towing vehicle, which limits the total weight the vehicle can safely tow. Exceeding this weight can lead to mechanical failures and unsafe driving conditions. This is another reason why only one vehicle is recommended to be towed at a time, as the combined weight of multiple vehicles could easily exceed the towing capacity of the tow vehicle.