North Carolina consists of three main geographic sections: the Atlantic Coastal Plain, which occupies the eastern 45% of the state; the Piedmont region, which contains the middle 35%; and the Appalachian Mountains and foothills. The extreme eastern section of the state contains the Outer Banks, a string of sandy, narrow barrier islands between the Atlantic Ocean and two inland waterways or "sounds": Albemarle Sound in the north and Pamlico Sound in the south. They are the two largest landlocked sounds in the United States.

How many main geographical sections make up North Carolina?