Final answer:
Retirees are less likely to have a credit card.
Step-by-step explanation:
In the given options, the segment of the U.S. population that is less likely to have a credit card is retirees.
Retirees are individuals who have reached the age of retirement and are no longer working.
Since they are no longer earning a regular income, they may be less inclined to use credit cards for purchases and may rely more on savings or other financial resources.