The correct answer is C) intensified intertribal competition and warfare.
Horses became so valuable in North America that they intensified intertribal competition and warfare.
When Spaniards brought horses from Europe to the Americas, the life on Native American Indians tribes changed in many ways. Horses did not exist in the Americas so they became very valuable for many tasks. Indians could travel to farther places, in less time and could transport goods because horses could carry heavy loads. When hunting buffalo, horse helped them to track them and hunt them more efficiently.
The other options of the question were A) were worshipped as gods. B) were very hard to purchase. D) were rarely used for hunting for the dangers implied. E) became the sole responsibility of men.