Compare and contrast experiments and observations

Which of the following statements best explains why there tends to be a greater number of large cities in southern africa than the east africa

One of the main reasons societies settled along rivers in the neolithic era was because a) the village elders demanded it. b) the land there was more valuable. c) it was more safe and secure there. d) it provided irrigation for farming.

How does central place theory explain patterns in the size and distribution of cities?