Card ONLY
If you grew up outside of the United States, you might be culture shocked to find out Americans prefer using their credit cards over using cash. Cash tends to provide a physical visual of how much money someone is carrying around with them instead of a card. Cash is also easier to steal and spend than trying to use someone else card, which can leave a trail.
In countries like Japan and other Southeast Asian countries, using cash is the most common currency exchange. The student’s experience in the U.S. with the cashier isn’t necessarily proof that anyone will steal your money here. But Americans do tend to be surprised when they see anyone handling a large amount of paper money.