GDP is the market value of all finished goods and services produced by a country's permanent residents, wherever located, in a year.

In a market economy, supply and demand are important because theya. (i) play a critical role in the allocation of the economy's scarce resources.b. (ii) determine how much of each good gets produced.c. (iii) can be used to predict the impact on the economy of various events and policies.d. all of (i), (ii), and (iii) are correct.