Answer:
It's D.
Step-by-step explanation:
The Monroe Doctrine stated the United States' intent to oppose future European colonization of the Americas. Therefore, the correct answer is D.
More:
Here is the key excerpt from the Monroe Doctrine, as delivered by President James Monroe in his seventh annual message to Congress on December 2, 1823:"The American continents, by the free and independent condition which they have assumed and maintained, are henceforth not to be considered as subjects for future colonization by any European powers... We should consider any attempt on their part to extend their system to any portion of this hemisphere as dangerous to our peace and safety."