The iron curtain has presented a major barrier to unifying the member nations of European Union.
Option A
Step-by-step explanation:
The European Union faced many challenges or barriers in the process of unifying all its member nations. One of the biggest barriers that the unification process faced was the Iron Curtain. Originally, the Iron curtain denoted a non-physical perimeter that split Europe into two separate divisions following the end of World War II in 1945 and remained in existence till end of Cold War in the year 1991.
Iron Curtain was an effort made by the Soviet Union to hinder itself from the contact of the countries present in Western Europe which were the members of NATO. This imaginary border was later transformed into a physical barrier that consisted of fences, watchtowers or lookouts, and even minefields. The infamous Wall of Berlin was also the part of Iron Curtain.