Why did the Monroe Doctrine make little impression on European powers?

Why did the Monroe Doctrine make little impression on European powers?

a. The Europeans were too occupied with losing their colonial power in the Americas to care about trade embargoes in the United States.
b. The Europeans did not see the United States as a significant enough military power to feel threatened about their support of Latin American independence.
c. Europe, especially England, could not predict how powerful an influence the United States would have on independent markets in Latin America.
d. Communication was so poor that the European powers did not receive news of the Monroe Doctrine until after they had given up Latin America.
e. Maps were so inaccurate that European powers did not have a sense of how close the United States was to much of Latin America.

ANSWER
B