As a result of new Portuguese forts and markets in Kilwa, Zanzibar, and Sofala, these Swahili port cities

Select one:

a. dropped out of the transatlantic slave trade.

b. became major trading centers.

c. saw their economies crumble.

d. were the most "European" of all African cities in the sixteenth century.

e. became the cornerstone of a vast Portuguese empire in East Africa.