Answer
The answer is B, the fall line is dividing the Piedmont and Coastal Plain geographic plain in Georgia.
Explanation
To fully understand the answer given above, let us define or describe as the case may be the terms in the question
Fall line: This can be refereed areas where an elevated region and a the littoral plain gets to meet and this is mostly visible where rivers meet or cross with resulting rapids or waterfalls. The elevated regions are usually hard and crystalline basement rock.
Geographic Plain: We need to first understand that geographic plain is the combination of two word, geography and plain.
In the study of geography, a plain is a leveled, land space that mostly does not have have any visible change in height or elevation.
In the case where we are referring to a valley, a plain can be enclosed on two sides. However, in other cases a plain may be delineated by a complete or partial ring of hills.
