Answer:
D. How Native Americans modified their environment
Step-by-step explanation:
Southeastern culture includes Southeast Indians that use to clear their fields for farming and grow new crops on the same land.
The Puebloan culture includes Native Americans, who developed a new way of irrigation using the Rio Grande. Native Americans or Puebloans developed this irrigation system based on floodwater farming and implemented stream diversions to the farmlands.
Hence, the correct answer is "D. How Native Americans modified their environment."