They weren't as accurate as they could be, in fact some were just based off of educated guesses.
Things like food shortage, war destruction, and weapons.
A)by providing water for irrigation and restoring trees to areas where forests once existed
Answer:
Correct answer is The US had a capitalist system, and the USSR had a communist system.
Explanation:
First option is not correct as democracy is a political, not economical system.
Second option is not correct, as United States fought against Socialism and Communism.
Third option is correct because Soviet Union had communist system, which included expropriation of land, while States developed Capitalism.
Last option is also not correct, due to facts mentioned before.