What types of vehicles require a CDL to operate?

The requirement for a Commercial Driver's License (CDL) is primarily based on the weight of the vehicle and the type of cargo it is carrying. A vehicle that has a gross vehicle weight rating (GVWR) of more than 26,001 pounds is classified as a commercial vehicle and necessitates a CDL for operation. Additionally, vehicles that transport hazardous materials, regardless of weight, also require a CDL due to the safety implications associated with such cargo.

This means that option C is the correct choice because it accurately identifies the criteria that determine when a CDL is necessary: either exceeding the specified weight limit or involving hazardous materials. This regulation ensures that drivers operating heavier and potentially dangerous vehicles have the requisite training and testing to handle the increased responsibility and risk associated with these vehicles.

Other options incorrectly imply that lighter vehicles or those carrying a limited number of passengers are subject to CDL requirements, which is not the case according to the regulations governing commercial driving. Therefore, understanding the specific weight limits and cargo classifications is essential for anyone seeking to operate commercial vehicles legally and safely.