Exploitation of solid minerals in developing countries can stabilize their revenue base mainly because it helps in

Step 1: Analyze the question The question asks why exploiting solid minerals (e.g., limestone, iron ore, tin, columbite, coal, gold) can stabilize the revenue base of developing countries. The key phrase is "stabilize their revenue base."

Step 2: Explain the concept Many developing countries, Nigeria included, depend heavily on one or two sources of income. Nigeria depends on crude oil, for example. This is a mono-economy. When the price of that product falls, government revenue crashes. This makes revenue unstable.

Stability comes from diversification, which means spreading income across many sectors. Developing solid minerals adds new sources of export earnings, taxes, royalties, and jobs, so a fall in one sector does not wreck the whole economy.

Step 3: Evaluate the options

• A. Promoting a mono-economy: Wrong. A mono-economy relies on a single product and makes revenue less stable, which is the opposite of the question.
• B. Transfer of technology: This can be a benefit of mining investment, but it is not the main reason for revenue stability.
• C. Diversification of the economy: Correct. It directly links to a stable and broader revenue base.
• D. Provision of energy: Only some minerals (like coal) give energy, so this is too narrow and does not address revenue stability.

Step 4: Answer The correct answer is **C. the diversification of the economy.

Tip: In Economics, whenever you see "stabilize revenue" or "reduce over-dependence on oil/one product," think diversification. And remember that "mono-economy" is usually the problem, not the solution.