Which of the following is required to signify a slow-moving vehicle?

A slow-moving vehicle sign is specifically designed to alert other drivers that the vehicle is traveling at a slower speed than the normal flow of traffic. This sign usually features a bright yellow background with a distinctive triangular shape, making it easily recognizable. The use of this sign is mandatory for vehicles that travel at or below a speed of 25 miles per hour, ensuring that other drivers can take appropriate measures to safely navigate around them.

While other options, such as safety cones or flashing amber lights, may be used in certain scenarios to enhance visibility or denote caution, they are not specifically designated for signaling the presence of a slow-moving vehicle on public roads. The red flag might be used in some situations for signaling purposes, but it does not serve the same recognized purpose as the slow-moving vehicle sign. Therefore, the correct identification of the required sign is crucial for ensuring safety and compliance with traffic regulations.