Answer:
D. Iron Curtain
Step-by-step explanation:
After the end of the second world war, the iron curtain was a political boundary that separated Europe into two different areas. The iron curtain had two sides, the East side and the West side. the Soviet union influenced those on the East side, while the West side had NATO member countries as well as some countries that were neutral.
The iron curtain was a political, military and ideological barrier which the East of Europe used to separate itself from having open contact with the West. It was Sir Churchill Winston who made the Iron Curtain speech given the behaviors of those in the Eastern part of the continent.