Final answer:
A desire to avoid further entanglement in other countries' issues.
Step-by-step explanation:
The reason that contributed to Americans turning towards isolationism after 1919 was c) A desire to avoid further entanglement in other countries' issues.
During this time, many Americans wanted to distance themselves from international conflicts and focus on domestic concerns. The traumatic experience of World War I and a desire to prevent future wars led to a strong isolationist sentiment among the American public.