How does the cpi provide an accurate indication of inflation within a country? a)the cpi uses a calculation to indicate how consumers spend more money on inferior goods as income rises. b) the cpi involves the calculation of price changes in the purchase of luxury items to indicate inflation. c) the cpi measures the average change over time in the selling prices received by domestic producers for their output using start and end dates. d) the cpi measures urban household spending on a "market basket" in a calculation to see how the average prices of goods and services have changed over time.