Which of the following is true regarding headlight assemblies?

Headlight assemblies must have DOT (Department of Transportation) or SAE (Society of Automotive Engineers) designations to ensure they meet specific safety and performance standards. These designations indicate that the headlights have been tested and certified for use on public roadways, providing assurance that they will offer adequate illumination and visibility under various driving conditions.

Using non-certified headlight assemblies may pose risks not only to the driver but also to other road users, as they may not function correctly or provide the necessary light output required for safe driving. This requirement helps to maintain uniformity in vehicle safety features and ensures compliance with road safety regulations, facilitating better visibility and reduced accident risks.

The other options do not align with the regulatory standards for headlight assemblies. For instance, while there may be various brands available, they must still be appropriately certified. Fully tinted headlights are generally not permitted, as they can impede visibility. Additionally, LED lights are not optional if the vehicle requires headlights; they must still meet the regulatory standards, including those mentioned regarding certification.