What MOST LIKELY would have happened in the absence of the Monroe Doctrine in "America's Place in the 21st Century World"?
A
Terrorism would not be a threat.
B
Europe would now include America.
America would have remained isolationist.
D
America would have become interventionist.

America would have remained isolationist

Explanation:

The Monroe Doctrine was simply a policy in the United States policy whereby European colonialism Wass opposed.

The most likely thing that would have happened in the absence of the Monroe Doctrine would be that America would have remained isolationist. This is because the Europeans would have had control over the country's goods and services.