Answer:
Between 1830 and 1850, immigrants who moved to American cities often faced crowded living conditions in poor neighborhoods. The Industrial Revolution opened many new job opportunities for people. Americans that lived in the rural areas of the country moved to the larger cities where the factories were located.
With what issue? Cause you didn’t write what there doing
Chemical factory fire, chemical spill turned the river red
If two countries claim the same region, generally, it likely leads to tensions between them, so you know that the answer is D). even without knowing specifically about India and Pakistan.
And it is: India and Pakistan have a very strained relationship and had even some military conflicts and nuclear arms race because of Kashmir.