Who believed that fluctuations in the business cycle were the result of class conflicts between labor and capital

Karl Marx

Explanation:

Karl Marx was a German economist that lived in the 19th century. His definition of capital as the most important factor of production was actually quite accurate and advanced for his time. He was the first major economist to state that capital by itself was enough to generate wealth.

He also proposed socialism as the higher stage of capitalism, which actually works in many European nations which are considered social democracies, e.g. Sweden, Norway, Denmark, Holland, Germany, etc., and at the same have the highest standards of living in the world.

Personally, I believe that his major flaw was to go a few steps further and believe in communism and that it would solve all of humanity's problems. Communism is not the same of socialism, since socialism believes in an economy under the influence of the state but also supports individual merit and private property. E.g. someone that works hard should be paid more, i.e. personal wealth is not bad. On the other hand, communism believes that the state must control the economy and that individuals should be rewarded based on their needs, not their work. It doesn't matter if you work hard or not even work at all, the state must satisfy your needs.

answerthe united states of america;

answer(d) all of the choices are correct;