What must every motor vehicle be equipped with?

Every motor vehicle is required to be equipped with a muffler. The key purpose of a muffler is to reduce the noise produced by the engine and exhaust system, which contributes to a more pleasant driving experience and helps comply with noise regulations set forth by law. Not only does this requirement promote a quieter environment, but it also plays an important role in ensuring that vehicles operate in accordance with local regulations on noise pollution.

While other options may relate to vehicle performance or safety, they are not universally mandated for all motor vehicles as the muffler is. For instance, tires, mud guards, and shoulder harnesses may be required for specific vehicles or in certain situations but are not a blanket requirement for every motor vehicle. The muffler stands out as an essential component that all vehicles must have to operate legally and responsibly on public roads.