Concept:Long-distance trade in pre-colonial Nigeria was shaped by geographic access to coastal and trans-Saharan routes.
Explanation:Before 1800, the Niger Delta was one of the most active trading zones in Nigeria.
Its coastal location allowed easy contact with European merchants arriving by sea.
Major Delta states such as Bonny, Calabar, and Brass became commercial middlemen.
They exchanged enslaved people, ivory, and local products for European manufactured goods.
The network of rivers and creeks made the movement of goods efficient.
The Sahara Desert is not a region within Nigeria, so option A is unsuitable.
The Lake Chad Basin and Benue River Valley were less central to the coastal long-distance trading system of this period.
Answer:B. Niger Delta