What color flag must be attached to a chain used for towing another vehicle?

Answer: B — White

The requirement for a white flag to be attached to a chain used for towing another vehicle is grounded in safety regulations. A white flag serves as a clear and visible signal to indicate that the vehicle being towed is actively engaged in an operation that could affect traffic and driver awareness. This visibility is particularly important in ensuring that other drivers can see the towed vehicle and recognize the need for caution, especially in varying lighting conditions or inclement weather. In many jurisdictions, regulations specify that using a flag of a certain color, such as white, is essential in promoting safety on the road. A white flag signifies that the vehicle is not just parked, but rather is in motion due to being towed, which helps prevent accidents that could result from a driver being unaware of the presence of the towed vehicle. The other options do not match the requirement specified in typical safety regulations, which can lead to confusion and may not effectively signal to approaching vehicles.