Correct Option: A. cowries, iron rods, brass rods, and copper rods Explanation of the Correct Answer: Before the introduction of formal money systems, various items were used as mediums of exchange in Nigeria and many other parts of the world. These items were often chosen based on their availability, durability, and the value that society placed on them.

1. Cowries: Cowrie shells were one of the most widely used forms of currency in many African societies, including Nigeria. They were valued for their beauty and rarity, making them a suitable medium for trade.
2. Iron Rods: Iron rods were also used as a form of currency. They were durable and could be used for various purposes, including tools and weapons, which added to their value in trade.
3. Brass Rods: Similar to iron rods, brass rods were valued for their metal content and were often used in trade. They were also used to create jewelry and other decorative items, which made them desirable.
4. Copper Rods: Copper rods were another form of currency. Like brass and iron, copper was a valuable metal that could be used in various applications, including crafting tools and ornaments.

The combination of these items reflects the diverse and practical nature of trade before the establishment of a standardized currency system. Why the Other Options Are Incorrect:

• Option B: iron rods, copper rods, manilla, and cowries
• While this option includes cowries and iron rods, it incorrectly lists "manilla" as a form of currency. Manilla is a type of bracelet or armlet that was used in trade, but it is not as widely recognized as a primary medium of exchange in Nigeria compared to the items listed in Option A.
• Option C: cowries, manilla, brass rods, and copper wires
• This option includes cowries and brass rods, but it incorrectly lists "copper wires." Copper wires were not commonly used as a form of currency in traditional Nigerian trade. Instead, solid forms of copper, like rods, were more prevalent.
• Option D: copper wires, brass wires, cowries, and iron rods
• Similar to Option C, this option incorrectly includes "copper wires" and "brass wires." The use of wires as currency is not historically accurate in the context of traditional Nigerian trade. The focus should be on solid forms of metal rather than wires.

Summary of Key Points:

• Cowries, iron rods, brass rods, and copper rods were historically used as mediums of exchange in Nigeria before the introduction of formal money.
• Cowries were valued for their beauty and rarity, while iron, brass, and copper rods were valued for their durability and utility.
• Other options incorrectly included items that were not primarily used as currency in Nigeria, such as manilla and wires.
• Understanding the historical context of trade items helps in grasping the evolution of currency systems.

Revision Summary:

• Cowries, iron rods, brass rods, and copper rods were key items used for exchange in Nigeria before money.
• Cowries were popular due to their aesthetic value; metal rods were valued for their utility.
• Incorrect options included items not primarily recognized as currency in traditional trade.
• Familiarity with historical trade practices enhances understanding of modern currency systems.