In Stage 2 of the demographic transition, what primarily decreases?

In Stage 2 of the demographic transition, mortality rates primarily decrease. This stage is characterized by improvements in healthcare, sanitation, and nutrition, which lead to a significant reduction in death rates, especially in infants and young children. As these improvements take effect, people begin to live longer, contributing to population growth since the birth rates remain relatively high during this stage.

The decrease in mortality rates is a crucial factor that differentiates Stage 2 from Stage 1, where mortality rates are high due to disease, famine, and lack of medical care. While fertility rates may eventually decline in later stages, during Stage 2, they typically remain high, so the population grows rapidly due to the declining mortality. This contrasts with the other options, which do not accurately reflect the primary demographic changes observed during this stage.