One of the most infamous of these political machines was Tammany Hall, the Democratic Party machine that played a major role in controlling New York City and New York politics and helping immigrants, most notably the Irish, rise up in American politics from the 1790s to the 1960s.
The fourth alternative is correct (D).
Monopolistic competition consists of an economic system where few companies compete with each other, but each has a relative monopoly power because they sell slightly differentiated products.
An example are the two telephone companies, which sell packages with price, minute, internet, etc. to compete for the same customer.
