Final answer:
The area of the Monroe Doctrine that aimed to free from European influence was the Caribbean.
Step-by-step explanation:
The area of the Monroe Doctrine that aimed to free from European influence was d. Caribbean. The Monroe Doctrine was a policy established by the United States in 1823 which stated that European powers should not interfere in the affairs of the Western Hemisphere. This included the Caribbean region, which saw significant American influence throughout the early twentieth century, asserting political, physical, and economic power in the area.