Answer :
in the 1950s, 40 percent of the U.S workforce was engaged in manufacturing, by the 2000s, fewer than 15 % percent of U.S workers were employed in manufacturing
This happens because most of the companies decided to manufacture their product in countries with lower wages such as South Asia and South America, which will increase their net income and add up their assets
The answer is B. 15%
On page 332 it explains that compared to 40 percent of U.S. workforce was engaged in manufacturing, fewer than 15 percent are still employed in manufacturing.