Answer:
C.The railroad opened up the Great Plains and the West Coast to waves of new immigrants from Europe.
Step-by-step explanation:
When the Transcontinental Railroad was finished transportation across America became easier, more goods were able to travel long distances for a shorter time which helped the development of industries and businesses.
The Transcontinental Railroad also made possible for the West to develop and catch up with the Eastern lifestyle, first because along the railroads cities started to develop and workers were needed which helped waves of immigrants from Europe.