According to Swahili Oral Tradition, the Founding of the Zanj

According to Swahili oral tradition, the founding of the Zanj ​

A) ​was due to the desire to convert to Islam.
B) ​an obstacle to prevent assimilation by the Malay peoples.
C) ​reflected the degree to which Africa merchants were tied into international trade.
D) ​brought Zoroastrianism to East Africa.
E) ​initiated the Indian ocean slave trade.