Which of the following best describes a used motor vehicle dealer?

A used motor vehicle dealer is best described as a person engaged in selling used vehicles for profit. This definition is key because it captures the primary role and objective of a used car dealer, which is to buy used vehicles, often refurbish or inspect them to ensure quality, and then sell them at a markup to consumers. This business model is centered around the resale of pre-owned cars, which differentiates used dealers from new vehicle dealers who focus exclusively on selling brand-new cars.

The other options represent different roles within the automotive industry. For example, a person who sells only new vehicles does not encompass the essence of used vehicle selling. A representative of a vehicle manufacturer typically works for the manufacturer to promote new vehicles, while an auctioneer of vehicles operates an auction, which is a different business model than directly selling cars to consumers. Therefore, option B accurately and succinctly defines the essence of what a used motor vehicle dealer does.