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.
By the 2000s, fewer than 5 percent of U.S. workers were employed in manufacturing. This decline from 40 percent in the 1950s was influenced by global competition, automation, and shifts in economic focus. Therefore, the correct answer is 'D. 5.'
;