A rapid population growth can result from

Step 1: Analyze the question The question asks which factor can cause rapid population growth. Population growth depends on birth rate, death rate, and migration. Growth is rapid when births far exceed deaths (a high natural increase).

Step 2: Explain the concept Natural increase = Birth rate − Death rate.

• Rapid growth happens when the birth rate is high and the death rate is low.
• Anything that lowers the death rate while births stay high will push the population up quickly.

Step 3: Evaluate each option

• A. High death and low birth rate: This gives a small or even negative natural increase, so the population would grow slowly or shrink. ❌
• B. The use of family planning methods: Family planning lowers the birth rate, which slows growth. ❌
• C. Absence of natural hazards: This might reduce some deaths, but it is not a major, direct cause of rapid growth. Many fast-growing countries still face hazards, and the effect is small compared with other factors. ❌
• D. Improved medical care: Better hospitals, vaccines, and treatment reduce infant and adult mortality and increase life expectancy. With birth rates still high, the population rises rapidly. This is the classic explanation for the population boom in many developing countries, including Nigeria. ✅

Step 4: Answer The correct option is D. improved medical care.

Exam tip: For population questions, ask yourself: "Does this raise births or lower deaths?" If yes, it speeds up growth. If it lowers births or raises deaths, it slows growth. Remember: Medical care ↑ → Deaths ↓ → Population ↑.