What specific evidence supports the statement that "the construction of the transcontinental railroad was disastrous for the native americans of the great plains"?
a) the transcontinental railroad opened frontier markets to new products and goods from the east.
b) within ten years of its completion, the railroad shipped $50 million worth of freight coast to coast every year.
c) the construction of the transcontinental railroad depended heavily on the labor of chinese and irish immigrants.
d) the transcontinental railroad decimated the herds of buffalo that the indians were dependent on; and the railroad drastically reduced native american land ownership.

The answer to the question is D.

Rail connections to the Great Plains proved especially devastating. After acquiring horses, Indians there had become heavily dependent on the plains bison for food, shelter, clothing, trade, and much more. In 1872 it was found that bison hides could be processed into commercial leather, and white hide-hunters immediately set out to meet that demand. Within a decade they had driven the millions of animals to the verge of extinction. The slaughter would have been unlikely, probably impossible, had railroads not provided the means to ship the hides and bones off to eastern factories. In one year near the end of the carnage, 1881–1882, the Northern Pacific shipped 2,250 tons of hides from the northern plains. Once the herds were gone, plains Indians had no true option but to turn to reservations and dependence on federal support. In effect the life blood of a people had bled away through the rail lines.

The answer to the question is D ;)