The first alternative is correct (A).
The Cold War opposed two powers aimed at dominating the world economic system. The US aimed at developing capitalism and expanding the democratic system, while the Soviet Union aimed to implement the communist system. Communist systems are characterized by state control of the means of production, so that usually only one party controls each communist country.
During 1989 and 1990, the Berlin Wall came down, borders opened, and free elections ousted Communist regimes everywhere in eastern Europe. In late 1991 the Soviet Union itself dissolved into its component republics. With stunning speed, the Iron Curtain was lifted and the Cold War came to an end.
The correct answer to this open question is the following.
I do not agree with what John Green said.
John Green stated that it might have been better if the Persians beat the Greeks. His arguments were that the Persian life was not bad. Persians ruled prosperous cities. And he comments that life was not easy in ancient Greece if you were a woman or a slave.
Of course, Greece was not perfect and had many issues. But the Persia Empire also had its many issues too.
I think it was good that Greece won the Persian Wars. The Greek victory established a foundation of a classical time in which Greece "exported" the idea of democracy to other states, as well as the philosophical ideas of great thinkers of Athens. Arts, literature, sculpture, and architecture were other important Greek influences that transcended the test of time.