The correct answer is - D. smaller soil deposits that require more artificial fertilizers.
The Aswan Dam is built in the southern part of Egypt, on the Nile River, thus making most of the Nile River flow through the country after this accumulation. This has resulted into the reduced flooding effect of the Nile River, thus reducing significantly the soil deposits that the river has been bringing with it. Because of this, the farmers have been forced to start to use more artificial fertilizers in order to get the amount of crops they previously did before the dam was built and stopped the natural process of fertilizing.