Which mountain range runs along the western edge of South America and forms a natural boundary between Chile and Argentina?

Which mountain range runs along the western edge of South America and forms a natural boundary between Chile and Argentina?

• A. Andes mountains
• B. Appalachians
• C. Alps
• D. Himalayas

Answer: (A)

The main idea being tested is recognizing which major mountain range sits on the western edge of South America and serves as a natural border between Chile and Argentina. The Andes run north to south along the Pacific coast, formed by the ongoing subduction of the Nazca Plate beneath the South American Plate, which lifts and shapes this vast range. Because political boundaries often follow prominent natural features, the Andes define much of the border between Chile and Argentina, creating a continuous geographic barrier between the two countries. It’s also the longest continental mountain range, reaching high peaks and including famous landmarks along its length. The other options are in different continents: the Appalachians are in eastern North America, the Alps in Europe, and the Himalayas in Asia. That geographic mismatch is why those ranges don’t fit the description.

The main idea being tested is recognizing which major mountain range sits on the western edge of South America and serves as a natural border between Chile and Argentina. The Andes run north to south along the Pacific coast, formed by the ongoing subduction of the Nazca Plate beneath the South American Plate, which lifts and shapes this vast range. Because political boundaries often follow prominent natural features, the Andes define much of the border between Chile and Argentina, creating a continuous geographic barrier between the two countries. It’s also the longest continental mountain range, reaching high peaks and including famous landmarks along its length.

The other options are in different continents: the Appalachians are in eastern North America, the Alps in Europe, and the Himalayas in Asia. That geographic mismatch is why those ranges don’t fit the description.