Southeast Asia. This is mostly because of the war
When the Japanese empire was dismantled at the end of World War Two, Korea fell victim to the Cold War. It was divided into two spheres of influence along the 38th parallel. The Americans controlled south of the line - the Russians installed a communist regime in the north, later ceding influence to China.
Your answer would be C since homeland defense is there to provide protection for the President with terrorism and dangerous crimes.