Concept:The Yoruba origin of the Oba of Benin is established mainly through the traditional account known as the Oranmiyan legend.
Explanation:After the Ogiso dynasty ended, Benin did not immediately have a king.
The people of Benin later invited Oranmiyan, a prince of Ife and son of Oduduwa, to rule over them.
Oranmiyan married a Benin woman, and their son Eweka became the first Oba of Benin.
This story, preserved in Benin tradition, is called the Oranmiyan legend.
It directly emphasises the Yoruba background of the Oba because it traces the royal dynasty to a Yoruba prince from Ife.
There was no direct relationship between the Oranmiyan and Ogiso dynasties, so that option is not correct.
The similarities in art and political structures are outcomes rather than the main evidence of Yoruba background.
Answer:D. Oranmiyan legend in Benin history.