While Maddie was browsing in a department store, a perfume salesperson presented her with a discount on a fancy perfume that Maddie usually can't afford. Maddie was very excited to buy her favorite perfume at a great price! Unfortunately though, the perfume Maddie was after was sold out. As she walked away disappointed, the salesperson informed Maddie that they found some gift sets with that perfume! The only issue was that they were not included in the sale and Maddie would have to pay full price. Which sequential persuasion technique did the salesperson use?

a. Foot in the door
b. Door in the face
c. Sweetening the deal
d. Bait and switch