To avoid the error of 'double counting' when calculating GDP, statisticians only count the value of final goods. Alternatively, they can calculate GDP by summing up the:

Correct answer: A) Value added at each intermediate stage of production

Explanation

To prevent counting the same resources multiple times (like the wheat in flour, and the flour in bread), statisticians either count only the final good, or sum the 'value added' at each production stage.