Final answer:
The Gross Domestic Product (GDP) is measured by factors such as consumer spending, investment spending, government purchases, and net exports. The factor not used in calculating GDP is industry purchases. Option B is correct.
Step-by-step explanation:
The Gross Domestic Product (GDP) is a crucial measurement of economic activity, and it is calculated by considering several factors. These include consumer spending, investment spending, government purchases, and net exports. The component that is not a factor in calculating GDP is B. industry purchases, as these purchases are internal to the production process and do not represent a final demand for goods and services within the economy. Therefore, when measuring GDP, we focus on the final market value of goods and services purchased by individuals, businesses, the government, and foreign buyers (net of imports).