Final answer:
The southern-most region in Georgia featuring barrier islands and the Okefenokee Swamp, bounded by the Fall Line, is the Coastal Plain. The correct option is A.
Step-by-step explanation:
The southern-most region in Georgia, known for its barrier islands and the Okefenokee Swamp, with its northern boundary marked by the Fall Line, is the Coastal Plain.
This region is part of a larger area that extends across the southeastern United States and is characterized by fertile fields, swampy salt marshes, and a vast expanse along the Atlantic Ocean and Gulf of Mexico.
The Coastal Plain spans from New England to Texas, made up of sediment that has been deposited since the eastern edge of the continent became tectonically inactive.