A. the Indus River Valley is associated with the region around the Indus River in South Asia.
B. the Nile River Valley is associated with the region around the Nile River in Northeast Africa.
C. the Fertile Crescent is a historical region in the Middle East known for its fertile land and includes parts of modern-day Iraq, Syria, Lebanon, Israel, Jordan, and Palestine.
D. the Great Plains is a vast grassland region in North America.
If you could provide more information or context about the region in question, I can give you a more accurate answer.