GDP (Gross Domestic Product) primarily measures the economic activity within a country and is commonly associated with options A and C. Here's a breakdown of the options in relation to GDP:
A: How many goods and services it produces in a year - GDP indeed reflects the total value of all goods and services produced in a country over a year, making this option accurate.
B: How long its people can expect to live on average - GDP does not directly measure life expectancy, although higher GDP can sometimes correlate with better healthcare and living standards that may improve life expectancy.
C: How much purchasing power the average citizen has - While GDP per capita can give an indication of average purchasing power, it does not account for income distribution or cost of living, so this is partially true but requires more context.
D: How high quality of life its people enjoy - GDP does not directly measure quality of life, which includes factors like health, education, and environmental quality. As with life expectancy, higher GDP can correlate with better quality of life, but it is not definitive.
In summary, the most direct conclusion you can draw about a country based on its GDP is option A: How many goods and services it produces in a year. Option C is also relevant, but it requires additional context regarding income distribution and living costs.