Name another national U.S. holiday.

The correct response is based on the understanding that all the listed holidays—Martin Luther King, Jr. Day, Labor Day, and Thanksgiving—are recognized national holidays in the United States. Each of these holidays holds significant importance within American society:

• Martin Luther King, Jr. Day, observed on the third Monday of January, honors the civil rights leader Martin Luther King, Jr. and his contributions to the movement for racial equality.

• Labor Day, celebrated on the first Monday of September, recognizes the contributions of American workers and the labor movement, marking a time to celebrate the achievements of laborers.

• Thanksgiving, observed on the fourth Thursday of November, is a day for giving thanks for the harvest and the preceding year, rooted in the cultural traditions of early American settlers.

Since each of these holidays is officially recognized and observed across the nation, stating that "all of the above" are national U.S. holidays is correct. This comprehensive acknowledgment reflects the diversity of American history and the values celebrated through these observances.