Concept:The pre-colonial Kingdom of Benin was famous for its skilled ivory carving and trade.Explanation:The Kingdom of Benin was located in what is now southern Nigeria.Its artisans produced intricate ivory carvings, masks, and ornaments.These items were highly prized and exchanged with European merchants along the coast.Other goods like gold, rubber, and salt were less central to Benin's early trade.Answer:A. Ivory