Answer:
Option A (Mississippi floodplain region) is the right approach.
Step-by-step explanation:
- The proportion of land anywhere along the river which is vulnerable to floods seems to be a floodplain. Throughout this continent, the water table is alluvial, simply means a river has accumulated it.
- Mississippi Floodplain Region organic dams need to pass this same progressive decline including its river basin, the Swamp, would be beyond the organic Levees.
All other options offered aren't relevant to the situation described. So, the right choice seems to be the one above.