Improved healthcare lowers birth rates via demographic transition

Steps:

• Recall demographic transition model: birth rates fall in later stages due to socioeconomic improvements.
• Identify factors reducing fertility: better healthcare decreases child mortality, prompting smaller families.
• Evaluate choices: link healthcare enhancements directly to reduced need for large families.
• Confirm C as the factor that aligns with falling birth rates in developing economies.

Why C is correct:

• In the demographic transition model, improved medical supplies and healthcare reduce infant mortality, leading families to have fewer children since more survive to adulthood.

Why the others are wrong:

• A: Fewer women working often correlates with higher birth rates, as it allows more time for childbearing.
• B: High infant mortality rates actually increase birth rates to compensate for child deaths.
• D: An increasing optimum population relates to resource capacity, not directly causing lower birth rates.

Final answer: C