__ refers to the total value of all goods and services produced by a national economy within a given period regardless of where the factors of production are located. A. Aggregate output B. Productivity C. Balance of trade D. Gross domestic product (GDP) E. Gross national product (GNP)

The correct answer is D. Gross domestic product (GDP). Gross domestic product (GDP) refers to the total value of all goods and services produced within a country's borders, regardless of the nationality of the producers. It measures the economic output of a country within a given period, typically a year or a quarter.