According to the text, the history of international relations:

A. did not begin in 1648

B. demonstrates that kingdoms, empires, city-states, and nation-states have for centuries interacted in the same kinds of patterns that continued after the end of the Thirty Years War

C. shows that China, Africa, India, and ancient Greece, and political units of various sizes had engaged in economic relations, exchanged ambassadors, and fought wars

D. all of the above