Tariff makes the most sense. Embargo is a ban on goods or a country, subsidy is money granted from the government to a business and has nothing to do with trade, quota is a limited amount of a product and again doesn't really have anything to do with trade.
There were many impacts on urban areas due to increased immigration. The biggest change to urban areas was the increasing number of ethnic enclaves or neighborhoods. These neighborhoods reflected the cultural elements of the homeland but with the freedom and values. These neighborhoods continued food, religious, and language traditions while immigrants adjusted to American life. Services to these neighborhoods eventually rose up like adjustment agencies and political boss systems. These "native" American systems helped and also took advantage of new immigrants but also served as a connection between American culture and the ethnic cultures.
