Answer:
The temporary division of Korea along the 38th parallel was a success for the policy of containment, as communism did not spread into South Korea. In 1954, SEATO (South East Asian Treaty Organisation) was set up as a copy of NATO. Communism had been prevented in South Korea and the UN was seen as a success.
Explanation:
As the first peaceful transition of political power between opposing parties in U.S. history, however, the election of 1800 had far-reaching significance. Jefferson appreciated the momentous change and his inaugural address called for reconciliation by declaring that, "We are all Republicans, we are all Federalists."
For more info http://www.ushistory.org/us/20a.asp
Teddy Roosevelt was also known as the trust buster. He helped to stop the monopolies and the robber barons.
The correct answer to this open question is the following.
The question does not include options. We do not know the name of the individuals you are referring to. You also did not mention what period in the history of the US you are referring to.
So although your question is incomplete, we can help you answer in the following general terms.
We assume you are referring to the Progressive era in the United States history from the 1880s to the 1920s.
During this era, many reformers demanded changes in US politics and economics. After many injustices lived during the Gilded Age, muckraker journalists exposed the corruption activities of many legislators and politicians. The federal government created legislation to stop this situation and also created laws to eliminate monopolies in the economy.
So we can say that reformers built a foundation to change the political and economic scene in the US, as well as society.