How did the building of the railroads impact Native American land?

The railroad disrupted intertribal trade on the Plains, and thereby broke a core aspect of Cheyenne's economic life.

Explanation:

The Transcontinental Railroad dramatically altered ecosystems. For instance, it brought thousands of hunters who killed the bison Native people relied on.

he construction of the Transcontinental Railroad had dire consequences for the native tribes of the Great Plains, forever altering the landscape and causing the disappearance of once-reliable wild game. Tribes increasingly came into conflict with the railroad as they attempted to defend their diminishing resources.

Explanation:

answer; (d) none of the above;

i believe the answer is:   psychological  experiment

in this experiment, wilhelm wundt became the first person that implement scientific method in analyzing the pyschological phenomenon.

due to this result, wilhelm wundt also able to make psychology to be acknowledged as a separate scientific field from biology.