I want to know the answer to the following question:
During what era was the central Sudan rich in environment?
All the background I'm provided with is that "During the Neolithic Era, before the onset of desertification, around 9500 BCE the central Sudan had been a rich environment supporting a large population ranging across what is now barren desert, like the Wadi el-Qa'ab.". Is that enough to answer the question?
Answer: yes