Both B and C can be correct answers.
International sanctions are used by the US goverment to protect national interests or international law. Impositions regarding economic, military or diplomatic issues are established until the existent threat no longer applies.
One crucial example of the US sanctions foreign policy has been the long lasting block to Cuban trade and the lack of diplomatic relationships during many decades with this country. The aim was to show the total opposition of the US to the Cuban regime and economic system, and to boycott it.