How did the railroad help change the prairie?
A.The railroad broke up the long, continuous stretches of the grassland where animals could roam freely.
B.They used coal as a fuel, which caused pollution that harmed the grasses.
C.Railroads frequently ran into bison and other animals on the tracks, which disrupted the ability of the animals to roam freely.
D.Railroads were very noisy, which scared animals and disrupted their living patterns.
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