No person shall aid, abet, or require a motor carrier to violate which set of rules?

The correct choice emphasizes adherence to the Federal Motor Carrier Safety Regulations (FMCSR). These regulations are crucial as they establish standards aimed at ensuring the safety of commercial motor vehicles and their operations throughout the United States. By prohibiting any person from aiding, abetting, or requiring a motor carrier to violate these regulations, it reinforces the accountability and responsibility of all individuals and entities involved in the transportation industry.

The FMCSR encompass a variety of important aspects including driver qualifications, hours of service, vehicle maintenance, and safety inspections, among other critical safety-related practices. Compliance with these regulations is vital in minimizing accidents and ensuring the overall safety of road transport operations.

In contrast, the other options, such as state transportation codes and occupational safety regulations, while also important in their own right, do not specifically govern the activities of motor carriers the same way that FMCSR does. National road safety standards might address broader traffic safety issues but lack the comprehensive and specific focus on the operational safety of motor carriers provided by the FMCSR. Therefore, the emphasis on the FMCSR in the context of this question highlights the importance of regulatory compliance specific to the commercial trucking industry.