Nationalism can unify a country by having a sense of superiority over other countries.
It would be that "c. the chairman of the veterans' bureau laundered nearly 200$ million" that was not a scandal associated with the harding administration, since this in fact happened during the previous term.
The best answer in regards to the specific question appears to be A: Many small towns boomed as people came to drill wells.
Alexander Hamilton was known to openly support Various forms of Federalist polciies, which are backed by bankers and wealthy businessmen.
At that time, the majority people in the north were influenced with anti-federalist ideology, so they would pretty much disagree with or even despise Hamilton's policies.
Image result for Which of the following countries was never a member of the League of Nations
The Soviet Union was the only country to be expelled by the League (in 1939, following its invasion of Finland). Despite formulating the concept and signing the Covenant, the United States never joined the League of Nations.
Member: Ecuador; Soviet Union