Kaitlyn wants to buy an airline ticket, but she’s uncomfortable taking that much cash to the counter at the airport instead, she uses her credit card which advantage of credit is being demonstrated here

A Emergencies
B Building a credit line
C Protection of purchases
D Purchase power

D Purchase power

By using a credit card to purchase the airline ticket, Kaitlyn is able to make a larger purchase than she would be comfortable making with cash. This demonstrates the purchase power advantage of using a credit card.