The answer is: Cities
Approximately, around 80% of united states population live in the cities. This happen because most of job opportunities that exist in united states (whether it's art, technology, or manufacturing) are located in the cities.
Because of this, even people who born in rural areas start to move to inner cities in order to find jobs and sustain their living.
The correct answer is C) the impact of the French Revolution.
Thomas Jefferson's reaction to the Jay Treaty as expressed in the letter was most directly a reflection of ongoing debates in the US over the impact of the French Revolution.
The Jay Treaty was signed by the government of the United States and Great Britain on November 19, 1794, in London, England. It was signed trying to resolve many difficulties and conflicts between the two nations after the Revolutionary War of Independence.
In a letter written to James Monroe on September 6, 1795, Thomas Jefferson expressed his concerns about the articles included in the treaty and the repercussions to the French government.
I think it was <span> over who would control appointments of church officials, a conflict which is sometimes called the Investiture Controversy. Hope this was useful :P</span>
C. Acueducts.
I'm sure that's it, good luck ;)