Which of the following pairs are recognized national U.S. holidays?

Independence Day and Thanksgiving are indeed recognized national U.S. holidays, celebrated across the country with various traditions and observances. Independence Day is celebrated on July 4th, commemorating the adoption of the Declaration of Independence in 1776, marking the birth of the nation. It is a day of patriotic celebrations, including fireworks, parades, and barbecues. Thanksgiving, celebrated on the fourth Thursday of November, is a time for families and friends to gather and give thanks, traditionally featuring a meal that often includes turkey and other seasonal foods.

In contrast, while Memorial Day and Labor Day (the first option) are also national holidays, they are not as universally recognized as Independence Day and Thanksgiving in terms of cultural significance. New Year's Day (the third option) is a national holiday, but Valentine's Day is not officially recognized as one; it is mainly a cultural celebration. Lastly, Christmas is a recognized national holiday, but Halloween is not; it is widely celebrated but does not have the same official status as a national holiday. Therefore, the pairing of Independence Day and Thanksgiving represents two of the most significant national holidays in the U.S., making the answer correct.