What does the Consumer Price Index (CPI) measure?

The Consumer Price Index (CPI) measures the average change over time in the prices paid by urban consumers for a market basket of consumer goods and services. This makes option B the correct answer, as it effectively captures the concept of the CPI measuring the average consumer's cost of living. The CPI is utilized to assess price changes associated with the cost of living, allowing economists and policymakers to understand inflation and purchasing power variations over time.

Other options pertain to different economic indicators; for instance, total consumer spending relates to overall economic activity, which the CPI does not measure directly. The total value of exports minus imports refers to the balance of trade, while the rate of unemployment is a separate measure evaluating the labor market. These distinctions clarify the specific role of the CPI in economic analysis, focusing solely on consumer price changes rather than broader economic metrics.