The federal government/principle
The US constitution differs from the Articles of Confederation because of the power that the federal government has. In the articles, each state acted as it's own country. They had the ability to command a military, declare war, and tax terrifs against other states. The constitution has the states act as subordinates to the federal government. They have the right to tax citizens, but their power and their ability to interact with other countries are strictly regulated through the federal government.
Answer:
B: In 1750, core areas of Europe and Asia enjoyed similar levels of economic development
