<human>: Question: During what era was the central Sudan rich in environment?
Answer: 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 the question answered in a satisfactory fashion?

OPTIONS:
- yes
- no
<bot>: yes