Answer: My guesses are...
B. Ghana lacked nearby water resources (because of the drought that was put upon them.) and E. Ghana did not have iron weapons and rival nations did.
I hope these are it and I hope that this helps you a little. Sorry if they aren't correct. I truly am sorry if they aren't. Good luck.
Try searching it up on Google. You can type this person's information and the time.
Universities would allow scientists to investigate their theories even if they contradicted Catholic teachings.