The first thing that has to be defined would be the scope of diplomacy since the other elements such as actors and tasks could only be determined according to how broad the scope is defined. When the term is taken in a narrow sense it usually describes political relations between states and includes the practices of the diplomats and ministries of foreign affairs. That is why history of international relations between states is defined as diplomatic history. Defining diplomacy as an instrument of foreign policy is not incorrect but is incomplete. In modern international relations it is no longer possible to define diplomacy only in terms of foreign policy or political relations between states that is carried out by statesmen and diplomats. The scope of diplomacy has expanded through the course of history. In several periods in history the scope of diplomacy has become a matter of discussion among the theoreticians and practitioners of diplomacy. Many have mentioned and accepted that there was old diplomacy and a new diplomacy. This points to the evolving character of diplomacy. Each era has a new diplomacy of its own. This is especially true for the twenty-first century. For this reason, it is necessary to adopt a broader approach. The correct answer is Choice C.