Concept:Industrial zones differ by the presence of factories, infrastructure, and urban markets.Explanation:Lagos-Ikeja is Nigeria's most prominent industrial zone.Porthacourt-Aba and Kaduna-Zaria are also known industrial centres.Lokoja-Ajaokuta is less industrialized compared to the others, despite having the Ajaokuta steel plant.Its overall industrial activity and supporting industries remain much lower than the other listed zones.Answer:A. Lokoja-Ajaokuta