The correct answer is A) Sumerians-Akkadians-Egyptians.
The correct chronology I have early floodplain civilizations is the following: Sumerians-Akkadians-Egyptians.
Indeed, the Sumerians were the oldest civilization that appeared on Earth, thousands of years ago. Historians considered that they settled in between the Tigris and Euphrates Rivers approximately 5,500 years ago, in what today is Irak, in the Middle East region. This civilization developed agriculture techniques and benefited from the flooding of these rivers to grow crops, prosper, and develop powerful city-states such as Lagash, Kish, Ur, and Uruk.