Answer:
Correct answer is by sending Soviet troops to Afghanistan.
Explanation:
Brezhnev doctrine was focused on the reaction of Soviet troops in the areas where the Socialism was endangered.
That is why the last option is correct as Soviets reacted with military assistance in Afghanistan.
All other options are not correct as they are showing the readiness of Soviet Union to lower the tension in certain period of crisis.
The Civil War influenced the role of government in the United States because it highlighted how the national government was the sovereign power. Following efforts by states to succeed and establish their own system of government the national government of the U.S. asserted is dominance and defeated the southern belligerents, thereby reasserting its dominance over politics and government in the United States following the war.
Assuming you're referring to Theodore Roosevelt, one of the most successful things he did in terms of regulating big business was the "break up the trusts,"--in that he took to court companies that were suspected of colluding with other firms and forming monopolies.
