Car salespersons are notorious for using the technique, which involves changing terms after an agreement has been made.
a. foot-in-the-door
b. foot-in-the-mouth
c. door-in-the-face
d. lowball

D) lowball

Explanation:

The lowball sales technique is used by salespeople who first offer a product or service at a low cost and then suddenly change some condition that increases the sales price.

For example, a car salesperson shows you a car and gives you a price. Once you have accepted that price, the salesperson says that the price was for the basic car trim and that the car you saw had a higher trim and therefore a higher price. If that doesn't work, and the client decides to purchase the car with the basic trim, the salesperson starts adding some extra expenses including but not limited to shipping and handling costs, taxes and sometimes even a fee for giving you the car clean and in a mint condition.

The key for a lowball sale is that the customer really likes and wants the product, and that the seller's argument for changing the price can convince the customer.