Concept:Pre-independence constitutions in West Africa created advisory and law-making bodies to support colonial rule.
Explanation:The Executive Council aided the colonial governor in administration.
Its members were mostly senior colonial officials.
The Legislative Council helped make laws for the territory.
It had official members and a few African representatives.
Together, these two councils formed the main structure of colonial governance.
Thus, the essential feature was the executive and legislative councils.
Answer:B. executive and legislative councils