Answer:
A. Afghanistan
Step-by-step explanation:
The Reagan administration in its anti-communism fight was helping countries that were against Communism and isolating countries that were pro-communists or had ties with communist States.
The administration took advantage of the huge doctrinal difference of the Sunni and Shia factions in Afghanistan to cause a political divide and alienate Afghanistan. This is an example of a classic "divide and conquer" scenario where two different factions are pitted against each other so they would grow weaker collectively and be easy to conquer.