Final answer:
Efficient taxation systems and strategic geographical location were two aspects of economic development that led to the success of the Hausa Kingdoms.
Step-by-step explanation:
Two aspects of economic development that led to the success of the Hausa Kingdoms were efficient taxation systems and strategic geographical location. The Hausa Kingdoms implemented effective tax systems that allowed them to generate revenue and fund their operations. Their strategic location along trade routes made them hubs for regional and trans-Saharan trade, enabling them to profit from commerce and accumulate wealth.