Some push factors were the chance to get rich, Dry farming, owning land, escaping the nightmares of the south ( slaves ). There were also longhorns to sell. Some pull factors were relatives and spouses not wanting them to go.
The railroad was able to aid others in communication, transportation, and products. An example is mail. People used trains to transport mail in order to communicate with others. Traveling was also cheaper and safer now with railroads since it was able to get people where they needed to be much more quickly. And finally products, manufacturers could send supplies to other places in a short amount of time much more easily.
Hope this helped
Its either C or D, but C seems closer.
