What is the main use of reflective triangles?

Answer: B — To warn other drivers of a breakdown

The main use of reflective triangles is to warn other drivers of a breakdown. When a commercial vehicle becomes disabled on the road, setting up these triangles a certain distance behind the vehicle allows oncoming traffic to become aware of the hazard ahead. This warning system is particularly crucial on busy highways or in low-visibility conditions, as it provides a crucial signal to other drivers to slow down and be cautious, preventing accidents and increasing safety for both the driver of the disabled vehicle and surrounding traffic. Reflective triangles are required by law in many states, and their visibility enhances safety during roadside emergencies.