how do the economists calculate gross domestic product (GDP)?

a. By adding up all the taxes collected by federal and state governments during one year.
b. By adding up all of the products, consumed within a nation during one year.
c. By adding up all of the goods and services produced within a country during one year.
d. By adding up all of the jobs that were added to a countries economy during one year.

c. By adding up all of the goods and services produced within a country during one year.