More hydro-electric power (H.E.P) projects should be constructed in developing countries because

Analyze the question: It asks for the best reason why more HEP projects should be built in developing countries. The key word is "should": we want the reason that creates the need or justification, not just a physical condition.

Concept: Hydro-electric power uses falling water to turn turbines. Building a project depends on physical factors (rivers, relief, rainfall), but the reason for building more projects is mostly economic and social. Developing countries are industrializing, urbanizing, and growing in population. That increases the need for electricity in homes, factories, and services. Nigeria, with its frequent power shortages, is a good example.

Evaluate each option:

• A. There is abundant rainfall: This is not true of all developing countries. Many, such as those in the Sahel, have low or seasonal rainfall. It is a favourable condition, not a justification.
• B. There is ever increasing demand for power: This is a strong reason. Growing populations and industries need more electricity, and HEP is a renewable, relatively cheap source in the long run. This explains why more projects are needed.
• C. Skilled labour is abundant: This is generally false. Developing countries often lack skilled engineers and technicians and rely on foreign expertise.
• D. There are many waterfalls on their rivers: Suitable sites exist, but not in every developing country. This is a site advantage, not the reason the projects should be built.

Tip: In "why should..." questions, look for the option that states a need or purpose (like rising demand) rather than a physical condition that merely makes the project possible. Also watch for absolute claims like "abundant," which are often false for developing countries as a group.