In what way have the physical characteristics of the Andean countries affected the population of the area?

a.The difficulties of navigating through the region made it more difficult for Europeans to settle the area.

b.Indian tribes who have lived for centuries at high altitudes have larger hearts and lungs.

c.The population is centered in the coastal lowlands regions, while the mountains and rainforests remain sparsely populated.

d.The isolation of the region has made marriage between Indians and Europeans far less common than in the rest of South America.