Describe a major factor in the longevity of the Swahili city-states' influence.

The major factor in the longevity of the Swahili city-states' influence is **b. the trade network that connected the city-states to other powers in the Indian Ocean**. The strategic location of these city-states along the East African coast facilitated trade with various civilizations, including those in the Middle East, India, and the larger Indian Ocean region. This extensive trade network allowed the city-states to thrive economically, culturally, and politically, enhancing their influence and sustainability over time. They were able to export valuable goods such as gold, ivory, and slaves, while also importing textiles, spices, and other commodities, making them integral parts of the regional and global trade systems.