The 14th Amendment provides citizenship to all persons born in the United States, among other things.
Hope this helps~
Benefits- The people have choice in who runs the country and which laws to place, and No rash decisions can be made without confirmation from multiple parties
Challenges- the first voting of the new leader, and setting up representatives for the new government
It would be a "b. mixed economy" that includes a laissez-faire ideal with government involvement to ensure competition fairness and protects public interest, since this is often seen as being the most productive kind of economy.
Assuming you're referring to World War II, the point at which U.S. actions were no longer neutral was when the Japanese bombed Pearl Harbor, since up until then the US had been a very isolationist nation that did not want to get involved in another European war.