Final answer:
A Buyers Guide must be displayed on both demonstrator or inventory vehicles and consignment vehicles for sale by dealers, according to FTC regulations, but it is not required for leased vehicles not currently for sale.
Step-by-step explanation:
The question pertains to the requirements for displaying a Buyers Guide in vehicles that are for sale. In the United States, the Federal Trade Commission (FTC) mandates that a Buyers Guide be displayed in all used vehicles for sale by dealers. The correct answer to the question of which vehicles must have a Buyers Guide displayed is both A and B. This means that both demonstrator or inventory vehicles (A) and consignment vehicles (B) must have a Buyers Guide visible for potential buyers. Leased vehicles that are not currently for sale do not need to exhibit a Buyers Guide. It's important for consumers to check the Buyers Guide information, which includes whether the vehicle is being sold "as is" or with a warranty, and what percentage of repair costs the dealer is obligated to pay.