Study the major mountain ranges on the map of the united states Which mountain range is marked with the letter D

The Appalachian Mountains.

Explanation:

Extending for almost 2,000 miles (3,200 km) from the Canadian province of Newfoundland and Labrador to central Alabama in the United States, the Appalachian Mountains form a natural barrier between the eastern Coastal Plain and the vast Interior Lowlands of North America.

7.03-1.70=5.33 and 6.80+5.09=11.89 and 5.5-3.01=2.49