Answer:
A: It is what our government is based upon.
Explanation:
Basically, we can eliminate B since the Constitution is just within the US. C doesn't make sense becuase the Constitution has been amended multiple times, and D does not work becuase the Constitution does not mention political parties.
The answer is A becuase the Constitution outlines the foundation and basis of America including core values & base-level ideologies/laws.
Because most countries involved in the war had alliances with others. And when one was attacked the ally came to protect the other. Therefore countries became more and more involved in the war
