Answer:
A. They made it easier for ranchers to ship their meat to eastern
cities.
Step-by-step explanation:
After the Civil War beef was in very high demand and that lead to the boom of the cattle business. This combined with the railroads meant that it was very easy for the ranchers to transport their meat to other cities. Before the railroads, it was impossible to ship meat a great distance especially since you needed half a year to get from California to new York.