Why did the tang dynasty face difficulties toward the end of its reign?
the economy struggled as china became unable to protect its long-distance trade routes.
the government suffered as friends were placed in official positions instead of skilled workers.
the economy struggled as peasants became unable to pay their increasingly higher taxes.
the government suffered as the line of succession became unclear after gaozong’s death.

i think it is B, im not 100% sure but i am 90% sure

Explanation:

It is that because the economy started to struggle with money and ect

c, they united with once

the correct answer is: the sioux followed the order and remained on the reservation.

after many confrontations between native americans and white american, in 1868, a reservation for the lakota sioux tribe was established in dakota territory, in this reservation they were able to hunt ad to move freely. in 1874, many sioux followed the order, given by the federal government, of remaining on the reservation in which they were already living. the problem arose when, in 1874, gold was found in that area by lieutenant george armstrong custer's military troops, and lieutenant custer insisted that the sioux must give up their reservation land in the black hill of the dakotas.

the united states government opted for moving the sioux to a new reservation. siting bull, leader of the lakota sioux, protested the united states government's demands for the lands where the lieutenant custer's soldiers found the gold. but finally they left the reservation lands and went to a camp along the little bighorn river in 1876.