Answer:
Correct answer is C) European Union .
Step-by-step explanation:
Option A is not correct as the Warsaw Pact was a military alliance of Communist countries in Europe that existed during the Cold War.
B is not correct as this is an idea not an organization or agreement.
D is also not correct as NATO is also military organization that includes countries outside Europe.
C is the only correct answer as EU is a political, economical organization whose goal is to create a free market for people and goods across Europe.