What significant change occurs in stage two of the demographic transition model?

In stage two of the demographic transition model, a significant change occurs where death rates decline while birth rates remain high. This stage is characterized by improvements in healthcare, sanitation, and nutrition, which lead to a decrease in mortality rates, particularly among infants and children. As a result, populations experience rapid growth since the high birth rates are not countered by an equally high death rate.

During this stage, families still tend to have many children, as societal norms and economic needs often encourage large families. However, the advancements that lead to lower death rates do not immediately affect birth rates. As a consequence, the result is a noticeable increase in the overall population size due to the gap between high birth rates and significantly reduced death rates.

Other options do not accurately describe the demographic changes typical of stage two in this model. For example, if both birth and death rates increased, the overall population would not experience growth. The option indicating that birth rates begin to decline pertains to later stages in the model when societies transition toward lower birth rates due to various factors, such as urbanization and access to family planning. The reference to a declining population would not apply to stage two, as this is a period of rapid population growth.