I believe A is the correct answer. Because the railroads made transportation of goods to other parts of America easier, the factories hired more people (especially those like immigrants who were willing to work cheaply) to make more goods.
A ;
The railroads significantly impacted European immigrants in America by creating job opportunities, particularly in construction and operating jobs in the railroad industry. Many immigrants found work in urban areas that relied on the railroads for economic growth. Hence, option A is the most accurate choice.
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