What made the Fertile Crescent so fertile?

A.
imported crops brought by foreign traders

B.
moderate temperatures in the summer

C.
heavy snowfalls in winter

D.
silt deposited by annual flooding

From Google:

Named for its rich soils, the Fertile Crescent, often called the “cradle of civilization,” is found in the Middle East. Because of this region’s relatively abundant access to water, the earliest civilizations were established in the Fertile Crescent, including the Sumerians.

The answer is D. silt deposited by annual flooding. The Fertile Crescent, located in the eastern Mediterranean region, was made fertile by the silt deposited by annual flooding. These floods brought nutrient-rich sediments from the Tigris and Euphrates rivers, creating a fertile soil that allowed for the growth of a variety of crops.

The correct answer is D. Silt deposited by annual flooding.

The Fertile Crescent was an area in the Middle East that stretched from the eastern Mediterranean coast to the Persian Gulf. The main reason why it was so fertile was the silt deposited by annual flooding from the Tigris and Euphrates rivers.

During the flood season, the rivers would overflow and deposit layers of nutrient-rich silt on the surrounding plains. This silt provided an excellent source of fertile soil for agriculture. The floodwaters also helped to replenish the groundwater, ensuring a steady water supply for crops throughout the year.

The other options - A. imported crops brought by foreign traders, B. moderate temperatures in the summer, and C. heavy snowfalls in winter - are not the primary reasons for the fertility of the Fertile Crescent. While the region did benefit from foreign trade and moderate temperatures, these factors were not the main contributors to its fertility.