Directions: Choose the appropriate word and fill the blank.

All countries have consumer price indices, some more reliable than others, some quite out of date, but all concerned with _______ overall price changes.

'Measuring' is correct because consumer price indices are statistical tools designed to track and quantify price changes over time. 'Controlling' is not the primary purpose, 'publishing' happens after measurement, 'reducing' is a policy goal not what indices do, and 'teaching' is irrelevant. CPI exists to measure inflation and price movements.