Which of the following physical features serves as a natural boundary that separates the Piedmont and Coastal Plain regions? Okefenokee Swamp Fhattahoochee River Appalachian Mountains

To determine which physical feature serves as a natural boundary that separates the Piedmont and Coastal Plain regions, let's analyze the options provided: 1. **Okefenokee Swamp**: This is a large swamp located in southern Georgia and northern Florida. While it is a significant geographical feature, it does not serve as a boundary between the Piedmont and Coastal Plain regions. 2. **Chattahoochee River**: This river flows along the border between Georgia and Alabama and is significant in the region. However, it primarily serves as a boundary between different states rather than specifically separating the Piedmont and Coastal Plain regions. 3. **Appalachian Mountains**: This mountain range extends from Canada down to Alabama and serves as a significant geographical feature. The Piedmont region is located to the west of the Appalachian Mountains, while the Coastal Plain region lies to the east. Therefore, the Appalachian Mountains act as a natural boundary between these two regions. Based on this analysis, the correct answer is the **Appalachian Mountains**.