The best example of how the United States adhered to the Reagan Doctrine in foreign policy is:
B. The United States sent troops to Lebanon to limit Soviet influence in the Middle East.
Explanation:
1. The Reagan Doctrine aimed to provide military and financial aid to anti-communist movements around the world to counter Soviet influence.
2. Sending troops to Lebanon was part of the broader strategy to limit Soviet influence in the Middle East by supporting Lebanese forces against Syrian-backed factions.
3. This action aligns with the principles of the Reagan Doctrine as it involved direct military intervention to combat perceived Soviet expansionism in the region.
This option demonstrates a clear application of the Reagan Doctrine by actively engaging in a conflict to prevent Soviet influence, making it the best example among the given choices.