Answer:
-- "The Silk Road" is an extensive intercontinental network of trade routes across the Asian continent connecting East, South, and Western Asia with the Mediterranean world, as well as North and Northeast Africa and Europe (and thus a network linking Eurasia).
Explanation:
D. All of the above all are economic
Birmingham: demonstrations, boycotts, and sit-ins. All these activities integrated the so-called Birmingham Campaign, as it was one of the most segregated cities in the US.
Washington D.C. : Martin Luther King's "I Have a Dream" speech delivered during the March on Washington for Jobs and Freedom in 1963 in front of 250,000 supporters of the Civil Rights Movement. It constituted a direct claim for the end of racism
Selma: police attacked peaceful marchers outside this city. The march which was peaceful in the beginning is nowadays known as the Bloody Sunday.
Watts: terrible riots took place here in 1965. A roadside incident escalated to a conflict with police and ended up causing six days of unrest.
Little Rock: students tried to integrate a school. This conflict required the involvement of the Supreme Court that issued the historic Brown v. Board of Education decision that declared segregated schools to be unconstitutional.
Montgomery: Rosa Parks refused to give up her seat in the bus in 1956 and it gave rise to the Montgomery bus boycott.
The term "Roundheads" was unofficially given to the supporters of the Parliament of England during the English Civil War--it was mostly derogatory.