Which statement is most accurate regarding the "miracle" of war production?
a. War production depended on the conversion of peacetime industries, so overall economic output grew very little
b. Both corporate profits and personal incomes increased, though more flexible smaller firms and wealthier individuals gained the most.
c. Worker productivity increased, due to new job opportunities after a long Depression than to commitments to the war effort.
d. US achievements in war production proved as important to the Allied victory as success on the battlefield.