What was the primary concern of the Monroe Doctrine?

The primary concern of the Monroe Doctrine was preventing European intervention in the Western Hemisphere, which is accurately reflected in the correct choice. Formulated by President James Monroe in 1823, this doctrine articulated a clear stance that the Americas should be free from further European colonization and intervention in political affairs. The underlying motivation was to protect the newly independent nations in Latin America from European powers that might seek to re-establish control or influence over them.

In essence, the Monroe Doctrine asserted that any attempts by European nations to interfere in the affairs of the Western Hemisphere would be viewed as acts of aggression and could provoke a response from the United States. It was built on the idea that the United States had a vested interest in maintaining the sovereignty and independence of its neighbors in the Americas, thus promoting regional stability.

The other options do not encapsulate the essential purpose of the Monroe Doctrine. Promoting trade with Europe, encouraging westward expansion, and establishing military alliances were not the doctrine's primary objectives. Instead, the focus was squarely on safeguarding the political autonomy of nations within the Western Hemisphere from external influences.