Answer:
A civilization is a complex culture in which large numbers of human beings share a number of common elements. Historians have identified the basic characteristics of civilizations. Six of the most important characteristics are: cities, government, religion, social structure, writing and art.
Explanation:
The correct answer is: A) Sanitation
Sanitation refers to the conditions that relate to public health, including the provision of clean drinking water as well as sewage disposal. The lack of basic sanitation leads to numerous problems. One of the most important is the death of thousands of children, over 525,000 of them dye every year because of diarrheal disease according to the World Health Organization.
Abundance of water was why, i might be wrong so dont quote me