Select the correct answer. Why was the Monroe Doctrine important to the United States during James Monroe's presidency?

A. The doctrine helped the United States form a military base that kept European nations at bay.

B. The doctrine prevented all European nations from declaring war on the United States.

C. The doctrine allowed the United States to partner with Britain and take control of Florida.

D. The doctrine enabled the United States to gain absolute power over Latin America.

E. The doctrine helped to boost American confidence in the United States.