The Year 1648 Represents a Dividing Line in European History

The year 1648 represents a dividing line in European history because

A) it was the year that Vasco da Gama landed at the Seven Cities of Cibola, bringing large amounts of silver and gold into the Portuguese economy, but also wage and price inflation.
B) the Sino-French war ended that year.
C) the Congress of Europe phase of diplomacy began, signaling a desire to end ethno-nationalism.
D) the Thirty Years' War ended that year, bringing with it a new template for relations in the international system.