Concept:The Benin pre-colonial government was built around a single supreme ruler, so it is best described as a monarchy.
Explanation:The Oba served as the monarch and the political head of the Benin Empire.
He held absolute authority, and no subject dared to challenge his word.
The Oba's position was hereditary, passed down within the royal lineage.
This arrangement does not match a unitary, parliamentary, or presidential system.
Instead, it is the defining feature of a monarchy, where one king rules with supreme power.
Hence, the pre-colonial Benin government was essentially a monarchy.
Answer:B. Monarchy