After Columbus' arrival in the Americas Ο Α.
the Ming dynasty stopped its voyages.
ОВ. the native population drastically declined.
O C. the Byzantine empire was conquered by the Ottoman empire.
O D. slavery was introduced to Africa.

B

Explanation:

After Columbus arrived they started the conquest of achieving land, therefore shutting down anything that lived within the land they wanted to conquer.

the federalist party which advocated strong centralization dominated the united states government till 1800. so 1800 election transformed the power from one party to another party for the first time and was thus a turning point in american history. so jefferson called it "revolution of 1800".

explanation:

letter a is the answer