One result of the expanding railroad system was that

a. native americans were able to protect the buffalo on the plains.
b. the mining and meat packing industries developed
c. chinese immigrants could leave new england and move west
d. the panama canal became less important for trade

answer asap!

B. the mining and meat packing industries developed

Explanation:

With the expanding of the railroad lot of industries flourished, including the mining and the meat packing industries. The reason for that was that the railroads managed to connect all the major cities and the part of the country, also enabling for much quicker movement of the goods from one place to another. Since this became possible, the industries quickly developed as they were able to sell their products on much larger distances with this new method of transportation, soon becoming one of the major and most profitable industries.