Gross Domestic Product (GDP) measures the total value of all final goods and services produced in a country during a specific period. It excludes intermediate goods to avoid double counting.
Among the options given, the lumber sold to a commercial construction firm would NOT be included in the calculation of GDP because it is an intermediate good, used in the production of final goods (like buildings), rather than a final good sold directly to consumers.
So the correct answer is:
Lumber sold to a commercial construction firm.