Answer:
c. only changes in prices
Explanation:
GDP deflator is used to calculate changes in price level or changes in inflation.
GDP deflator = (Nominal GDP / Real GDP) × 100
Nominal GDP is GDP calculated at current year prices.
Real GDP is GDP calculated at base year prices.
GDP is the sum of all final goods and services produced in an economy within a given period which is usually a year.
I hope my answer helps you
