Concept:Peaceful relations between states or groups is the core function of diplomacy.Explanation:Diplomacy is the art of managing international relations through dialogue and negotiation.Diplomats are trained representatives who handle communication between governments.They work to resolve conflicts peacefully and build cooperation between nations.Therefore, peaceful relationships arise mainly from the activities of diplomats.Other agents like the media or security agencies support peace but do not primarily conduct official state-to-state relations.Answer:C. diplomats