Based on the reading what might be the cause of growing settelments

Witch one is it soo it the the question b.a,b,c,d

Which modern technology has not made a great difference in the inuit way of life?

Which ecosystem best fits the characteristics listed below? which ecosystem best fits the characteristics listed below? ii. seasonal migrations of millions of wildebeests, zebras, and elephants iii. large numbers of predators, such as lions iv. acacia trees and grasses a. the congo rainforest b. the african mangroves c. the serengeti grasslands d. the sahel