Answer:
D. Farming and medicine
Step-by-step explanation:
When they arrived in America, the Europeans found a populated territory. Its inhabitants, however, were ignorant of writing and left no documents about their own past. The knowledge we have about the native tribes of the 16th century is mainly based on accounts and descriptions of European travelers who were here at the time.
These travelers report that the Indians survived from hunting, fishing, extractivism, and had great advances in agriculture. They settled in the valleys of navigable rivers, where fertile lands existed. They stayed in place for about four years. After the natural resources of the place had been exhausted, they migrated to another region with better resources for agriculture. Travelers also report that the Indians were advancing in medicine, which was based on medicinal plants, but effective for many health problems.