Final answer:
Ancestor worship was not common in Christianity and Islam before they were spread in Africa. Therefore, the correct option is A. ancestor worship
Step-by-step explanation:
The belief or ritual that was not common in Christianity and Islam before they were spread in Africa is A. ancestor worship.
Ancient African religions, which were polytheistic, often practiced ancestor worship as a way to honor and seek guidance from deceased ancestors. However, monotheism, the belief in only one god, was a core tenet of both Christianity and Islam. Festivals and prayer, on the other hand, were common practices in both Christianity and Islam and still continue to be prevalent in these religions today.