One of the major cause of Cold War between the US and Soviet Union was the ideological difference between them. US propagated and aimed at spreading the idea of Capitalism while the Soviet Union wanted to spread Socialism.
Soviets feared that Western promotion of capitalism could pose a threat to thier idea of socialism. They grew hostile and intolerant towards Western capitalistic ideology and practice. Consequently, this ideological difference between the two superpowers contributed to the rise of Cold War.
In the late 1800s, American cities suffered from serious environmental pollution due to the smokestack emissions from hydroelectric power plants. The correct answer is D.
