Final answer:
The Piedmont region of Georgia is separated from the Coastal Plain by the Fall Line, a natural border marked by waterfalls and rapids.
Step-by-step explanation:
The boundary that separates the Piedmont region of Georgia from the state's Coastal Plain region is B) the Fall Line. The Piedmont region consists of lower, rolling hills and small isolated mountains, while the Coastal Plain is characterized by a relatively flat, low-lying area that extends from the Atlantic Ocean.
The Fall Line is a geographical feature that represents the transition zone where the hilly or mountainous lands meet the plain.
Due to the differences in elevation, rivers descending from the higher Piedmont to the lower Coastal Plain create waterfalls and rapids, marking the location of the Fall Line, which acts as a natural border between these two distinct geographical regions.