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.
Under Kublai Khan the Mongol empire reached its largest extension. He ruled over 24000000 km² (nearly 10000000 mi²). The empire went from China and Korea to Iran and southern Russia, from the Korean peninsula to the Danube River.
During Kublai's reign the empire was divided into four smaller Kanatos but he still remained as the Great Khan of all of them. He was actually the first Khan to successfully conquest China in 1279, making him the first Yuan ruler of the whole China. After his death, the mongols didn't elect a new Khan and the Kanatos became more independent.
People who live in the authoritarian system do not have an effective way to restrain the power of the rulers
Eastern merchants banded together to reject the barter economy in Europe
I'm gonna go with B; A, C, B.
Alexander the Great ruled from 331 - 323 BC, the Han Dynasty started in 206 BC and ended in 220 AD, and finally the Mongol empire began in 1206 AD and ended in 1368 AD.
Hope this helps!