What is unlawful to operate on a highway regarding vehicle wheels?

Answer: B — Flanges or lugs on wheels

Flanges or lugs on wheels are unlawful to operate on a highway because they can compromise the safety and functionality of the vehicle. The presence of such modifications can interfere with the proper operation of the steering and suspension systems, leading to unpredictable handling and a greater risk of accidents. Furthermore, these features could cause significant damage to the road surface and increase the likelihood of tire blowouts, endangering not only the driver but also other road users. In contrast, worn tires, large rims, and slick tires may pose significant safety concerns and could result in legal issues depending on their condition and performance on the road. However, the specific prohibition on flanges or lugs directly addresses the impact of these modifications on vehicle operation and roadway safety, setting a clear standard for acceptable wheel functionality.