The correct answer is A. Centered around rivers that flooded regularly
Step-by-step explanation:
The Egypt, Sumer, and Harappa were some of the first civilizations in the world, inDeed Sumer civilization is considered as the earliest civilization that emerged around 4500 BC. All of these civilizations were centered around rivers because this allowed human groups to grow crops, herd animals and have water all the time which make possible permanent settlings that change previous nomadic life. In the case of Egypt civilization, this developed around the Nile River in Africa; in the case of Sumer civilization, it developed around the Euphrates River and Tigris River in the Middle East and finally, the Harappa Civilization developed around the Indus River.