In very broad terms it is possible to separate diplomatic relations between states into two, depending on the number of actors, as bilateral diplomacy and multilateral diplomacy. Whereas bilateral diplomacy defines relations between two states multilateral diplomacy defines the relations between more than two such actors. As is defined in the Vienna Convention on Diplomatic Relations, the establishment of diplomatic relations between States, and of permanent diplomatic missions, takes place by mutual consent. (Article 2) Establishing diplomatic relations is only one of the facets of recognition for states. Likewise being accepted to an international organization is a sign of acceptance in a broader sense. Recognition by itself does not require the establishment of diplomatic relations but is a necessary prerequisite for establishing diplomatic relations. Similarly breaking of diplomatic relations does not mean the withdrawal of recognition. Breaking up of diplomatic relations is a unilateral act, realised by an announcement of any of the states, on the contrary to bilateral agreement of establishment. States establish mutual relations usually with an agreement that can be in the fashion of an announcement, a joint decision, exchange of notes or issuing of a communiqué and in some rare cases states just encounter without any kind of agreement but just the implication of having agreed to have relations. The correct answer is Choice C.