When the nile flooded what did it leave behind?

A-small islands

B-mounds of grain

C-large stones

D-rich black soil

When the nile flooded, it left behind the black silt that was pivotal for agriculture, due to the abundance of nutrients.

Answer: Rich soil

Explanation: The river Nile left behind rich soil when it flooded ... when the flood water receded, the farmers were able to cultivate the land and get a rich vein of crops for feeding all the people making up the civilization near the river banks of Nile.