Name two national U.S. holidays.

The correct answer includes Memorial Day and Labor Day, which are both established national holidays in the United States. Memorial Day, observed on the last Monday of May, honors military personnel who have died in service to the country. Labor Day, celebrated on the first Monday in September, recognizes the contributions of American workers and the labor movement.

While there are other holidays mentioned in the options, they do not all qualify as national holidays. For example, Christmas is indeed a national holiday, but Easter is not officially recognized as one. Halloween and Valentine's Day are widely celebrated but do not have the status of national holidays. Thanksgiving, although a national holiday, is paired with Halloween, which is not. Veterans Day is a national holiday, but pairing it with Valentine's Day does not reflect two national holidays. Therefore, the pairing of Memorial Day and Labor Day stands out as they are both recognized US holidays.