The traditional assumption on foreign policy has been that states – and actors representing them – think and act in a rational manner. Under this traditional assumption these actors decide in consideration of all present alternatives, through a process that is focused on utility-maximization, while suffering minimum costs, in the best interest of the country and every effort is made to achieve the relevant information on the situation. This idea led to the understanding of the state as a blackbox – a unitary actor of internal differences of which, does not have any relevance pertaining to its foreign policy actions. In other words, regarding their foreign policies all states act upon a certain set of principles, affecting them in similar ways, which stem out of their ontology as states. Such an essentialist approach renders issues like; ideological or psychological predispositions of the decisionmakers, or differences of governmental systems, regime types, ideas or policymaking processes irrelevant. Hence, it takes systemic constrains to the core of foreign policy. It also assumes the existence of a prevailing understanding of the national interest that is mostly static and immune to changes in international politics. The notion “National Interest” is “used generally in two senses in IR: as an analytical tool identifying the goals or objectives of foreign policy and as an all-embracing concept of political discourse used specifically to justify particular policy preferences. In both senses, it refers to the basic determinants that guide state policy in relation to the external environment. It applies only to sovereign states and relates specifically to foreign policy: the internal variety usually being characterized as ‘the public interest’

As can be understood from the information given, the correct answer is E. All statements in the options can be used in order to describe the term  “National Interest”.