What must a salesperson carry while selling or driving a vehicle with a dealer plate?

A salesperson must carry a pocket ID while selling or driving a vehicle with a dealer plate. This identification serves as proof of the salesperson's affiliation with the dealership and validates their authority to operate a vehicle with dealer plates. It is essential for regulatory compliance, as it demonstrates that the individual has been properly licensed and trained in accordance with state laws governing automotive sales.

The other options, while potentially useful in a sales context, do not provide the necessary identification required during the operation of a dealer-plate vehicle. A business card may help in establishing professional identity but does not serve as official identification. A sales contract is important for the sale process but isn’t required to be carried in the vehicle. Vehicle registration, while relevant to the legal operation of a vehicle, is typically associated with the vehicle itself rather than the individual salesperson.