Vehicles carrying more than ____ lbs of propane must have placards on ____ sides.

The correct option signifies that vehicles carrying more than 1001 pounds of propane are required to display placards on four sides. This requirement is crucial for safety and compliance with regulations concerning the transportation of hazardous materials, including propane.

When vehicles transport significant quantities of propane, proper identification and warning systems, like placards, play an essential role in alerting other motorists and emergency responders about the potential hazards associated with the load. By displaying placards on all four sides of the vehicle, it ensures maximum visibility and awareness in case of an emergency or roadside incident.

The specified weight limit of 1001 pounds is significant as it marks a threshold where the risk of harm increases, necessitating stronger measures for safety and communication. Understanding these protocols is key for anyone involved in the transportation of LP-gas, as it highlights the critical nature of adhering to safety guidelines in order to prevent accidents and ensure safe handling of the material.