Final answer:
Chinese immigrants were hired to build the Transcontinental Railroad because they were willing to undertake the work others rejected(option d) , which often included the most dangerous tasks. These laborers were crucial in the completion of the railway that was essential for the U.S. industrial expansion post-Civil War.
Step-by-step explanation:
In order to build the Transcontinental Railroad, Chinese immigrants were hired by the railroad companies because they were willing to do the work that others refused to do. Chinese laborers were seen as indispensable to the railroad construction, particularly for carrying out the most dangerous and challenging tasks. This was during a time when there was an intense need for labor to connect the Eastern and Western United States, aiding the expansion and commercial development of the nation.
The majority of Chinese immigrants came to the U.S. in search of work opportunities on the railroads and the Gold Rush, but they ended up facing grueling and underpaid labor conditions. After the Civil War, the completion of the Transcontinental Railroad was crucial for the industrial expansion of the United States, which included advancements in steel manufacturing and other innovations, heralding America's growth into an economic powerhouse.
The working conditions faced by the Chinese immigrants were severe, often working long hours for low pay in a challenging environment. However, the determination and resilience of these laborers were significant in completing the monumental project of creating a unified railway system across the United States.