Concept:A mountain’s “peak” is its topmost point, while its “base” is the ground level from which its height is measured.Explanation:Mount Everest rises about 8,848 metres, or roughly 5.5 to 6 miles, above its base.This vertical distance is measured from the base upward to the peak.The word “depth” is used for something below a surface, such as an ocean.“Source” refers to the starting point of a river, and “root” is part of a plant.Thus, the phrase “six miles from its base” correctly describes the height of Mount Everest.Answer:A. base