None of the given options directly increase when productivity increases. However, increased productivity can positively impact the economy, potentially leading to an increase in gross domestic product (A) and a decrease in national unemployment rates (C). Interest rates on loans (B) and savings (D) are typically influenced by other factors such as central bank policies and market conditions. Higher productivity can indirectly contribute to a more favorable economic environment, which could have an impact on interest rates in the long run.
