Answer:
American protectionism ( D )
Step-by-step explanation:
American protectionism in the 19th century made the Great Depression to be felt worldwide, because it was geared towards protecting made in America products against foreign competition i.e placing heavy tariffs on imported goods that could be produced in America. at the time of the great depression America was doing everything possible to revive the economy and put its citizens out of Misery and one way was to push the effect worldwide while protecting its own.
The American market is a very large market and many European goods were been exported to America and the increase in Tariffs on imports meant that the American market has been narrowed to American products only which left a huge economy loss on other countries making them feel the effect of the great depression as well.