What defines a gross weight?

Gross weight refers to the total weight of a vehicle when it is fully loaded, which includes the weight of the vehicle itself, any cargo it is carrying, and any additional equipment that may be attached. Therefore, the correct answer is determined by this comprehensive definition.

In this context, option C is correct because it accurately describes gross weight as encompassing not only the vehicle but also its cargo. This is fundamental for various legal and regulatory reasons, including ensuring that vehicles do not exceed weight limits that might affect safety and infrastructure.

The other options do not encompass the full definition of gross weight. For instance, the weight of the vehicle alone does not consider any additional load it might carry, while the weight including passengers or the driver also falls short of accounting for cargo. It is important to recognize the total load on the vehicle to ensure compliance with transportation laws and to maintain vehicle safety on the roads.