The correct answer is D) they all relied on farming.
The other options of the question were A) most of their population were enslaved. B) they issue coins as money. C) they relied very little on trade.
The economies of ancient Mesopotamia, Egypt, and the Indus Valley were similar in that they all relied on farming.
We are talking about ancient civilizations on planet Earth. These civilizations benefited from the flooding of the rivers that made the soil very fertile for agriculture. The Sumerians settled between the Tigris and Euphrates Rivers in the Middle East region of what today is Iraq. The Egyptians settled in next to the banks of the Nile River. The Indus Valley civilization did the same, but next to the Indus River.
