When did the kingdoms of Ghana and Mali flourish?

When did the kingdoms of Ghana and Mali flourish? A. 100 - 400, during the era when Christianity was founded and organized B. 400 - 1400, during the era when the Roman Empire declined, the Byzantine Empire flourished, and Islam was founded C. 700 - 1200, during the era when Islam was founded and the Muslim Empire spread D. 1100 - 1600, when the Middle Ages ended and kings assumed great power in Western Europethe anwser is b