Answer :

Assuming this is referring to the same list that was posted before, the correct answer is that almost all nations share in similar cultures and a sense of unity.
Greenleafable
A nation is a group of people who share a common history and a common national identity. It was an idea that started spreading during the age of Romanticism in the 18th and 19th century when nationalism started rising since countries wanted to get their independence from huge monarchies such as the Austria-Hungary or the Ottoman empire.