The correct statement about the Monroe Doctrine in relation to expansion in the Western Hemisphere is:
It stated that the US would not tolerate European colonialism in the Western Hemisphere.
The Monroe Doctrine, articulated in 1823 by President James Monroe, asserted that the Western Hemisphere was off-limits to new European colonization and warned that any intervention by foreign powers in the affairs of the Americas would be viewed as a hostile act against the United States. This doctrine effectively established a sphere of influence for the U.S. in the region, discouraging European intervention and allowing for American expansion and influence throughout the Western Hemisphere.