Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.Prehistoric horses were far removed from the horses that Christopher Columbus brought on his ships during his second voyage to the New World. Although fossil remains of “dawn horses” have been excavated in several sites in Wyoming and New Mexico, these animal, which were biologically different from contemporary horses, had been extinct several millennia before ...

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.

Prehistoric horses were far removed from the horses that Christopher Columbus brought on his ships during his second voyage to the New World. Although fossil remains of “dawn horses” have been excavated in several sites in Wyoming and New Mexico, these animal, which were biologically different from contemporary horses, had been extinct several millennia before onset of the Indian era. Although moviegoers visualize an Indian as a horse rider, Indians were not familiar with horses until the Spanish brought them to Mexico, New Mexico, Florida, and the West Indies in 1519. Those that escaped from the conquerors or were left behind became the ancestors of the wild horses that still roam the southwestern regions of the country. The Indian tribe scattered in the western plains began to breed horse about 1600.

The arrival of the horse produced a ripple effect throughout the Great Plains as the Indians living there were not nomadic and engaged in rudimentary farming and grazing land hunting. Tracking stampeding herds of buffalo and elk on foot was not the best way to stock quantities of meat to adequately feed the entire tribe during the winter. However, mounted on horses, the hunting team could cover ground within a substantial distance from their camps and transport their game back to be roasted, dried into jerky, or smoke for preservation. The hunters responsible for tribe provisions stayed on the move almost continuously, replacing their earth-and-sod lodges with tepees. Horses carried not only their riders but also their possessions and booty. The Blackfoot Indians of the Canadian plains turned almost exclusive hunters, and the Crow split off from the mainstream Indian farming in favor of hunting. In fact, some of the Apache splinter groups abandoned agricultural cultivation altogether.

The horse also drastically altered Indian warfare by allowing rapid maneuvering before, during, and after skirmishes. With the advent of the horse, the Apache, Arapahoe, and Cheyenne established themselves as territorial monopoly in the Plains. Because Indians did not have the wheel and had dragged their belongings from one settlement to another, horse also enabled them to become more mobile and expedient during tribal migration. In fact, the Cheyenne abolished the custom of discarding belongings and tepee skins simply because there were no means to transport them.

According to the passage, how many genetic species of horses are known today?