Correct Answer: Consumer Price Index (CPI)

Solution : The correct answer is (d) Consumer Price Index (CPI)

Consumer Price Index (CPI) is not a measure of national income. The Consumer Price Index is an indicator of the average change in prices of a basket of goods and services consumed by households over time. It is used to measure inflation and changes in the cost of living. In contrast, Gross Domestic Product (GDP), Gross National Product (GNP), and Net Domestic Product (NDP) are measures of economic activity and income within an economy. They represent the total value of goods and services produced, either domestically or by the country's residents, after accounting for depreciation.