Correct Option: C. a convenient medium of exchange Explanation of the Correct Answer: A convenient medium of exchange is crucial for the development of commercial activities in any economy, including Nigeria. Here’s a step-by-step breakdown of why this option is correct:

1. Definition of Medium of Exchange: A medium of exchange is an item that is widely accepted in transactions for goods and services. In modern economies, this is typically money, which can take the form of coins, banknotes, or digital currency.
2. Facilitating Trade: The existence of a convenient medium of exchange simplifies transactions. Before the introduction of money, barter was the primary method of trade, which required a double coincidence of wants (both parties needing what the other offers). This limitation hindered trade and economic growth.
3. Increased Efficiency: With a convenient medium of exchange, individuals and businesses can easily buy and sell goods and services without the complications of barter. This efficiency encourages more commercial activities, as people are more willing to engage in trade when they can easily use money.
4. Encouragement of Savings and Investment: A reliable medium of exchange allows individuals to save and invest. When people trust that their money will hold value, they are more likely to save for future purchases or invest in businesses, further stimulating economic growth.
5. Expansion of Markets: A convenient medium of exchange enables the expansion of markets beyond local communities. It allows for trade over larger distances, connecting producers and consumers in different regions, which is essential for a diverse economy like Nigeria's.

Why the Other Options Are Incorrect or Weaker:

• A. A good transport system: While a good transport system is important for facilitating the movement of goods, it is not the primary factor that enables commercial activities. Without a medium of exchange, even the best transport system would not lead to effective trade. Transport systems enhance trade but do not initiate it.
• B. The indigenization decree: The indigenization decree aimed to promote local ownership of businesses and resources. While it played a role in economic development, it did not directly facilitate the day-to-day commercial activities that rely on a medium of exchange. The decree may have encouraged local entrepreneurship, but it did not address the fundamental need for a reliable currency.
• D. A high level of production: High production levels are beneficial for an economy, but they do not guarantee commercial activity. If there is no effective medium of exchange, even high production cannot be effectively traded. Production needs to be matched with a system that allows for the exchange of goods and services, which is where a convenient medium of exchange becomes essential.

Summary of Key Points:

• A convenient medium of exchange simplifies transactions and encourages trade.
• It increases efficiency and allows for savings and investments, stimulating economic growth.
• While transport systems, indigenization decrees, and production levels are important, they do not directly facilitate commercial activities like a medium of exchange does.
• Understanding the role of money in commerce is crucial for grasping economic development in Nigeria and other economies.