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.  

from the conditions of the working class in england by friedrich engels,the main idea is :

b is the answer i am assuming