10 6. As a reaction to European threats, one of the Presidents said that
further colonization of the Americas by European countries is prohibited.
This statement is known as-*

Washington's farewell address.
Separation of Powers
The Monroe Doctrine.
The Judiciary Act of 1789.

c the monroe doctrine

Explanation:

In a speech to Congress in 1823, President James Monroe warned European powers not to attempt further colonization or otherwise interfere in the Western Hemisphere, stating that the United States would view any such interference as a potentially hostile act.