Which option most accurately explains the significance of the Monroe Doctrine?

It served as a precedent for hemispheric domain in American foreign policy.
Explanation:
The Monroe Doctrine warned Europe not to colonize or take over nations in the western hemisphere.
Answer:
Explanation:
Monroe Doctrine was a U.S. policy, opposing European colonialism in America. As textually says: "the manifestation of an unfriendly disposition toward the United States.". Also, this Doctrine also will respect and recognise all colonies that are already settle in the America.
So, basically Monroe Doctrine was to ensure a foreign policy against Europe.