B) tracking changes in the consumer price index
The consumer price index (CPI) is a key measure of inflation and reflects changes in the price level of a basket of consumer goods and services. It provides insight into the economic impact of government decisions, particularly in relation to monetary policy, fiscal policy, and overall economic conditions faced by households. Changes in CPI can highlight the effects of government policy on purchasing power and living costs, making it a suitable choice for evaluating economic impact on society.