Answer:
C) They are along a plate boundary in which plates are currently converging, causing uplift and steep slopes.
Step-by-step explanation:
The Andean Mountain Range is by far the longest and highest mountain range in South America, and one of the largest in the world as well. Its formation is due to the convergent plate boundary between the South American plate and the Nazca plate. The Nazca plate is an oceanic plate, while the South American plate is a continental plate. The Nazca plate subducts bellow the South American plate, causing uplift in the area near the subduction zone. This has resulted in lifting up of the land, slowly creating the steep and very high Andes. The plate boundary is still active in the same way, so the process still continues.