Answer:
A. An American effort to rebuild the war-torn nations of Europe
Explanation:
Direct exposure to dirtiness/filth and dead things/decay. You would think you would get a disease if you accidentally fell into a pile of dead animals.
The FOUR features of the Marshall Plan that helped to restore Europe's economy were: named after a US Secretary of State, aid to countries damaged during World War II, resulted in increased trade between nations, and offered to all European nations