The influx of immigrants in the united states in the second half of the 19th century most directly led to which of the following?
a. the formation of cultural neighborhoods where people from the same country/region could support one another.
b. the establishment of political reform groups focused on expanding voting rights for immigrants..
c. the failure of the railroad.
.d. the passage of the sherman anti-trust act

A. The formation of cultural neighborhoods where people from the same country/region could support one another.

Explanation:

This is the way places such as Chinatown and Little Italy were born in large American cities. Immigrants tended to look for fellow immigrants from their own country of culture as a way to find mutual support, solidarity.

could you go a bit more in depth with you question? it's quite hard to understand. as soon as you do that i will be glad to : )

answer; a cost benefit analysis;