What Is One Reason That Students of International Relations Should

What is one reason that students of international relations should study history?

A) Historically,the world was a more peaceful place than today; therefore,the past offers clues as to how to achieve peace today.
B) Core concepts in the field,such as sovereignty,were developed and shaped by historical events.
C) Since the international system has remained unchanged over time,there are many parallel situations in the past that are relevant today.
D) Contemporary international relations mirror patterns often seen in the Chinese and Indian civilizations of the past.