The Civil War (1861–1865) was the root of which modern-day belief(s)

The Civil War (1861–1865) was the root of which modern-day belief(s)?

(a) The Thirteenth Amendment of the Constitution, which prohibits slavery and involuntary servitude in the U.S.
(b) The belief that wars can stimulate industrialization.
(c) The belief that wars can effectively mobilize resources, boost employment and heighten production without inflationary consequences.
(d) All of the above.

ANSWER

(a)