The author' s attitude toward the treatment of American Indians by whites is of ______.

A．Buffalo dead bodies were left rotting in the sun by whites.
B．Nearly fifteen million buffalo were killed within twenty years.
C．More than half of the great buffalo herd had disappeared by 1869.
D．The railroad brought necessary food and supplies to the white settlers.

A．the U.S. government' s policies towards the American Indians were shameful
B．the land that the Indians fought to retain belonged to them
C．numerous abuses were among the results of the rail roads' rapid spread
D．the U. S. army could not be considered a friend of the American Indian