Concept:In the pre-colonial Yoruba political system, the supreme ruler was the king, known as the Oba.
Explanation:The Yoruba, particularly in the Oyo Empire, placed the Oba at the head of government.
He was also called the Alaafin of Oyo and combined both political and spiritual powers.
As the highest authority, he made final decisions, aided by councils and chiefs.
The Ogboni, Oyomesi, and Balogun were all subordinate groups below the Oba.
Therefore, the Oba alone held supreme authority in the Yoruba pre-colonial era.
Answer:The highest authority was the Oba (Option B).