Recall the Application About the Size of Wal-Mart to Answer

Recall the Application about the size of Wal-Mart to answer the following question(s) . During 2008, Wal-Mart's sales were approximately $374 billion, or roughly 2.6 percent of U.S. GDP, and its cost of sales was $286 billion.
-According to this Application, by using a value-added approach to measure Wal-Mart's sales impact on the economy, we are

A) using a chain-weighted index.
B) avoiding double-counting.
C) including GDP as a measure of welfare.
D) excluding the net foreign sector.