The name of the human was lucy
The neolithic era began when some groups of humans gave up their pneumatic hunter gatherer lifestyle completely to the beginning farming. It may have taken humans hundreds or even thousands of years to transition fully from the lifestyle of subsisting on wild plants to keeping small gardens and later trending large crab feilds.
After the Vietnam War ended, immigration by Vietnamese refugees skyrocketed. Also, American soldiers began bringing home Laotian brides from the country of Laos, called Hmong. This is why the United States has a large Hmong population in the Midwest.
The answer to your question is D (the last)