D. Decolonization and nationalism
Following World War I, the message of self-determination or countries choosing their own government became important. As a result, the modern era has seen colonies gain independence. These new countries have established their own governments and sense of identity. Looking at the development of these newly independent countries gives historians a new set of country development to analyze as well as studying how countries around the world have become more intertwined.
The continent of Africa and many Asia countries have developed during the modern era. These areas were released from European control and for the first time in around a century had the ability to control their own government. New cultural norms were established giving these new countries a chance to build their identity. Many used nationalist movements to regain their identity such as the Vietnamese.