i think its C becuase its talking about what they left behind
C. Nutrient rich soil
A great amount of very fertile soil was left on its banks, thereby allowing crops to be grown.\t
When the Nile flooded, it left behind nutrient-rich soil known as silt, which was essential for agriculture in ancient Egypt. This fertile soil allowed the Egyptians to grow crops and sustain their civilization. Therefore, the answer is C. nutrient-rich soil.
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