PLEASE HELP
Which of the following factors contributed to the rapid growth of the cattle industry between the 1860s in the 1880s?

A. Ranchers on the plains begin to raise sheep.

B. Farmers settled on the plains and fenced in their fields.

C. By the mid-1880s there were more cattle on the open range then the land could support.

D. As railroads spread into the west it became easier and more profitable to ship cattle from the west to large cities in the east in the mid west.