Answer:b
Explanation:
got it correct on unit test
A) Railroads
Railroads helped to transport resources, manufactured goods, and people all over North America, greatly speeding up the industrialization of the entire continent, especially the United States. Where as industrialization previously existed mostly along coastal cities where materials could quickly be shipped to and from industrial centers, the entire continent was now much more easily accessible for this.
The correct answer is:
D. It had to be rebuilt from almost nothing.