Answer: B. Bait and switch.
Explanation: Bait and switch is a fraudulent sale tactics aim at deceiving customers by placing advertisements for a low price of a product "bait", but when the customer gets there to buy the product it become unavailable then another product with higher price is introduced to the customer " switch".
In this case Biff was made to believe he can get a Nissan for $15,000 but on arrival the salesman claims product sold out and then introduced him to a different truck with higher price which was the salesman plan initially.