A) Businesses struggled to replace skilled workers killed or severely injured in the fighting.
Explanation:
From 1915 the US got tons of loans to the UK to support them in their war effort. It is not a range to say that WWI was the significant factor in providing to the Roaring 20s when the US economy expanded. The long-term outcome was that US engagement in the warheads straight to the Great Depression and WWII.
The main way in which World War I hurt business in Europe even after the war was that Europe was economically devastated and had focused all their production on war materials, which means there was a lot of goods and services after the war.
Many former slaves still were unedumercated and needed to find jobs this lead to a legal form of work known as share cropping (tending to crops for a portion of the crop or a low wage pay)