Which terms must new vehicles NOT be advertised using?

Answer: D — Both "invoice" and "cost"

New vehicles cannot be advertised using the terms "invoice" and "cost" because these terms can imply a misleading representation of the price that a dealer pays for the vehicle. These words may create an impression that the advertised price is the same as what the dealer has paid, which can mislead consumers about the nature of vehicle pricing. The use of such terminology may not reflect the true costs associated with acquiring the vehicle, including additional expenses or overhead, and is subject to regulations that aim to prevent deceptive advertising practices. In contrast, terms like "below market" may convey a different message regarding perceived value or pricing strategy, but they do not carry the same implications of misleading pricing as "invoice" and "cost." Therefore, it is essential for automotive salespeople to avoid using "invoice" or "cost" in advertisements for new vehicles to maintain transparency and comply with advertising regulations.