Many people who immigrated to the United States during the Gilded Age moved to...
Urban areas, where they worked in factories.
You see, many businesses opened factories in urban areas, creating jobs, so immigrants moved to these areas in order to work for these new companies.
It would be D, it's about survival with nature. kind of like man vs nature. (which you'll learn in high school)
I believe it is B—California was admitted as a free state.
The emperor gained stronger power
The world of heaven in my opinion