Which of the following was a continuity in the development of african states in the period circa 1200—1450

Despite geographical barriers, some African states were able to maintain diplomatic and cultural contacts with the broader Afro-Eurasian world.

Explanation:

The continuity of the diplomatic relationships allow trade during 1200-1450 which help the development of what is known as the Swahili coast market.  

This Market integrated the following countries:

Kenya, Tanzania, Mozambique, Somalia, Comoros.

The trade had the following dynamic, African countries would sell gold, ivory, species and the Arabs, would sell finished products from china and species from India.

This trade with eurasia was vital in this period to develop the african nations.