Where should safety marks indicating the presence of dangerous goods be placed on a vehicle?

Answer: B — On each side and each end of the trailer or transport unit

Safety marks indicating the presence of dangerous goods must be placed on each side and each end of the trailer or transport unit to ensure visibility from multiple angles. This placement allows for immediate recognition of hazardous materials by other road users and emergency responders, which is crucial for safety. The standardized labeling system helps to communicate the type of dangerous goods being transported, allowing for proper precautions to be taken in case of an incident. Choosing to place these marks only on the back, on the windshield, or on the driver's door would not provide the necessary visibility required for effective hazard communication. It would limit the ability of people around the vehicle to identify potential dangers, especially in situations where the vehicle may be approached from the side or rear. Therefore, the requirement for comprehensive marking on all sides of the transport unit reinforces safety protocols and regulatory compliance.