Much of south america falls within the tropical humid and tropical wet and dry climate zones, as indicated by the two shades of purple on the above map. which of the following statements best explains why much of the western coast is colored dark brown? a. the dark brown represents the marine west coast climate zone. b. the dark brown represents the arid climate zone: the western portion of the continent is a desert. c. the dark brown represents the highland climate zone, and the andes mountains are located along the western portion of the continent. d. the dark brown represents the highland climate zone, and the sierra madres are located along the western portion of the continent.

The correct answer is C. The dark brown represents the highland climate zone, and the Andes Mountains are located along the western portion of the continent.

Explanation:

The Andes is a large, elongated mountain range along the west coast of South America. The mountain area is approximately 7000 km long, in some places 160 km wide and has an average height of approximately 4000 m. The mountain range runs for the most part parallel to the coast of the Pacific Ocean.  Its highest peak is 6,959 meters high in Aconcagua, Argentina.

The Andes are the southern part of the mountain range that runs from North America (Rocky Mountains), through Central America to South America. They are the result of the insertion of a marine plate in the subduction zone under the continental plate.

The Andean chain is located in seven South American countries: Argentina, Chile, Bolivia, Peru, Ecuador, Colombia and Venezuela. The Andes crosses the equator and runs south to Tierra del Fuego. The Scotia Arc, with South Georgia and the South Sandwich Islands among others, is a largely undersea continuation of the mountains. This connects the Andes with a large arc to the Antarctica.