Concept:The economy of Nigeria’s forest zone was based on agriculture and exchange of goods.
Explanation:In the eighteenth century, the forest zone had fertile soil suitable for crop cultivation.
The people produced cash crops, especially palm oil and palm kernels, for trade.
Trading was also a major economic activity, linking forest communities with coastal and inland markets.
Pastoral farming, salt-making, and cotton weaving were not the main features of the forest zone in this period.
Answer:D. cash crop production and trading.