Which of the Following Was Not True of the Swahili

Which of the following was not true of the Swahili peoples of east Africa?

A) Those who lived in urban areas usually converted to Islam.
B) The main reason for their city-states was commercial
C) The Swahili traded up and down Africa's east coast as well as far into the interior.
D) Slave trading was never a large part of the Swahili trade network.
E) Many Swahili who lived in remote areas never converted to the Islamic faith.