How Did the Influx of Migrants from the Arabian Peninsula

How did the influx of migrants from the Arabian peninsula affect the lives of the coastal people of East Africa?

A) The migrants had little to no influence as they remained strictly segregated from the indigenous peoples.
B) The Arabs introduced a strict social and racial hierarchy to the native culture and prohibited marriage between Arabs and Africans.
C) The migrants introduced Islamic culture, intermarried with Africans, and helped form a society that combined Asian, African, and Islamic traits.
D) The Arabs aggressively spread Islamic culture throughout the region and suppressed more traditional religious beliefs and cultural practices.