The preparatory work (travaux préparatoires) is, in general terms, the record of the drafting of a treaty, including the records of negotiations between the participating states and, in some cases, the records of the work of independent bodies of experts. Preparatory work may be a manifestation of the common intention of the parties to the treaty.

The Universal Declaration of Human Rights was adopted in 1948.

Article 1 of the 1933 Convention on Rights and Duties of States (the Montevideo Convention) provides that “the state as a person of international law should possess the following qualifications: (a) permanent population; (b) defined territory: (c) a government; and (d) capacity to enter into relations with other States.”

In a particular dispute before the ICJ, its search for relevant rules takes it to the treaties, which are expressly recognized by the parties, or to general practice accepted as law (by States), or to general principles of law (recognized by States). If the conventions, practices, and principles are not found relevant or clear, the Court may resort to “judicial decisions and the teachings of the most highly qualified publicists” as “subsidiary means for the determination of rules of law”. It may take into account the decisions of the international organs.

The mandate system was created after the First World War under Article 22 of the Covenant of the League of Nations to deal with the future administration of the overseas possessions of the “Axis” states of Germany and the Ottoman Empire. Three categories of mandates (A, B and C) were devised for those territories “according to the stage of their development” (Art. 22 of the Covenant of the League).

Accession is normally a final act of a state to be bound by a treaty; it does not require ratification unless so provided in the instrument of accession. Therefore, the correct option is E.

The doctrine of non-recognition, commonly called the Stimson Doctrine of non-recognition, implies the withholding of recognition from new territorial titles or territorial changes brought out by use of force or through any other act of doubtful character.

An entity, to be considered a state, must have certain characteristics, such as territory, population, government, and sovereignty

A formal source is that from which a rule of law derives its force and validity. The material sources, on the other hand, are those from which is derived the matter, not the validity of the law. From formal sources, the law derives its authority or sanction. The procedures or methods by which rules become legally binding are formal sources of law.

All of them are among the sources of international law in Article 38 of the Statute of the International Court of Justice.

Audi alteram partem: Hear the other side (let the other side be heard as well).
Estoppel: A rule of evidence or a rule of law that prevents a person from denying the truth of a statement he has made or from denying facts that he has alleged to exist.
Res judicata: The principle that when a matter has been finally adjudicated upon by a court of competent jurisdiction it may not be reopened or challenged by the original parties or their successors in interest

The Declaratory theory considers that a new state or a new government exists independent of recognition.

There are two requirements for a custom to be accepted as law: (i) there should be sufficiently uniform general practice accepted as law, and (ii) the belief that such a practice is obligatory. Consequently, for a practice or usage to become a customary rule of international law, the following two factors are essential:

• A material fact: in similar circumstances States act similarly, in other words, usage has been constantly and uniformly practiced by States. 

• A psychological element: (opinio juris sive necessitatis) (an opinion of law or necessity) - the feeling on the part of States that in acting as they act they are fulfilling a legal obligation.

The two are often referred to as the objective (material) and subjective elements of custom respectively

States that are subject to the authority of one or more states are known as “dependent states.” The notion of dependence necessarily implies a relation between a superior state (e.g., protector etc.) and an inferior or subject state (e.g., protégé etc.); the relation between the state which can legally impose its will and the state which is legally compelled to submit to that will.

When the State practice is either ambiguous, non-existent,
sparse, or contradictory, courts get involved in determining the rules of law in order to decide a legal issue and in this process they create new rules. Decisions rendered by the courts are of immense value; and in those cases where there is no preexisting
rule, these decisions become a direct source of law.

There are difficulties in applying the essentials of Statehood to non-self-governing territories - colonies, protectorates, trusteeship and mandate territories. The correct answer is C.

Ubi Societas Ibi Jus is a legal maxim which means ‘where there is society, there is law’. The correct answer is D.

Estoppel [from Norman French estouper, to stop up]: A rule of evidence or a rule of law that prevents a person from denying the truth of a statement he has made or from denying facts that he has alleged to exist.

The law derives its authority or sanction from formal sources.

The Vienna Convention defines treaty as “an international agreement concluded between states in written form and governed by international law”