In the 1800s, what was the most important motivation for both “old” and “new” immigrants to settle in ethnic neighborhoods?

The answer is common language.  It could also be common culture since they are all from the ethnic race, it promotes a sense of community where people feel safe knowing that they are among their fellow countrymen in a new land.  

the answer is b. hope this !

explanation:

an oligopoly is a term used to clarify the structure of a particular market, industry, or organization. a market is considered oligopolistic or amazingly focused when it is shared between a few companies.