Name a national U.S. holiday?

All of the choices listed—Labor Day, Thanksgiving, and Memorial Day—are recognized as national holidays in the United States. Labor Day, celebrated on the first Monday of September, honors the American labor movement and the contributions of laborers to the country’s development. Thanksgiving, observed on the fourth Thursday of November, is a time for families to come together and give thanks, often celebrated with a large meal. Memorial Day, which occurs on the last Monday of May, commemorates those who have died in military service to the United States. Since each of these holidays is officially recognized at the national level, selecting "All of the above" encompasses all three as valid responses. This highlights the importance of each holiday in American culture and reinforces the practice of recognizing multiple significant observances within a single answer.