Which of the following is one legacy from the empires of Mali and Songhai?

One legacy from the empires of Mali and Songhai is that the languages they established are still spoken today. These empires contributed to the promotion of various languages, particularly the Mande languages, among others in the region. While the hajj was an important Islamic tradition, it was not established by these empires. The assertion about oral laws is broader and not specifically tied to the legacies of Mali and Songhai. Christianity, on the other hand, did spread in some areas, but the empires themselves were primarily centers of Islamic scholarship and culture.