Pools were agreements between railroad corporations to divide the business in a given area and share the profits. Many companies formed these pools in order to avoid competition by dividing business in a particular area. Efforts to regulate the monopolizing practices of railroad corporation then first came in the form of action by the supreme court.
I say A) Economic Decline
The correct answer is:
B. Relocation to suburbs.
Relocation to suburbs has been a constant of urban life since the early 1900s.

Isolationists were people who pulled away from involvement in foreign affairs. This mainly happened after WWI. U.S.A did not want to become involved with the League of Nations.The League of Nations was a group of countries that tried to create world peace. The Americans did not want to be entangled into another war with the Germans.
ativism is a term that is used to mean the opposition of immigration. Nativism favored the primary race of the country (White). This was a post WWI trend. Millions of Europeans were seeking to immigrate in other parts of the world and many of them tried to come to the United States. Many Americans mainly did not like the Germans because they started the war. Many Americans were nativists and had prejudices
Against the German people.
The Emergency Quota Act was a movement that limited the number of immigrants each year that emigrated to the U.S. All of these topics affected politics in the 1920’s, especially the Quota System. This favored all western Europeans and created a drop in immigrations for the U.S. The Americans did not play any German music. Also, they wouldn’t allow the Americans to speak German.
Answer:
Among them, the United States and Britain agreed not to seek territorial gains from the war, and they opposed any territorial changes made against the wishes of the people concerned. The two countries also agreed to support the restoration of self-government to those nations who had lost it during the war.
Explanation: