The correct answer is A.

IRT is a theory to explain the peace and cooperation among nations. As it is known, peace and order can only be explained by realist writers through the concepts of national interest and selfish interest, but functional theories explain it through the benefits of international organizations. On the other hand, according to liberals, peace and order can only be achieved by the increase in the number of democratic states. Therefore, the correct option is B.

A world federation of peaceful states was introduced by Kant as a recipe to solve the security demands of states

The term 'English School' was first coined by Roy Jones in a 1981 article titled 'The English School of International Relations: A Case for Closure' in which Jones argued that a group of scholars, basically gathered at the London School of Economics, could be taken as forming a distinct school of international relations and this could could be referred to as the 'English School'.

Until the First World War, most countries in Europe were on the gold standard. Yet with the war, the system collapsed, because of the declining power of Great Britain and of the terrible economic conditions during and after the war. Even though there were some efforts to return to the safety of the gold standard in the second part of the 1920s, this did not last long due to the stock market crash, or the Great Depression, in late 1929. The Great Depression was the worst economic crisis in the history of the industrialized world, lasting from 1929 to roughly 1939. The correct answer is D.

The purpose of regimes is to form a frame for facilitating the solution of problems through treaties. Regimes as Jervis stated are not only making the cooperation easier in short run, but also in the long run, providing an environment of cooperation for promoting relations. Therefore, the correct option is A.

Self-determination is about the right of the people of a particular place to choose the form of their government.

Keohane also pointed out that regimes should be differentiated from treaties in a certain subject. A treaty can be ad hoc in character but also would be narrow in terms of subject matter and parties. However, regimes are not always limited to a certain subject and not interim provision.

The G20 is made up of 19 countries and the European Union. The 19 countries are Argentina, Australia, Brazil, Canada, China, Germany, France, India, Indonesia, Italy, Japan, Mexico, Russia, Saudi Arabia, South Africa, South Korea, Turkey, the United Kingdom, and the United States. The correct answer is E.

The correct answer is A.

J.J. Rousseau developed the idea of the European federation.

Rawl’s concept of justice founded the background of new economic order demands of poor Third World countries to fill the rift between North and South (Viotti and Kauppi, 1993: 534).

The nationalists believe that closing off an economy to external influences can be beneficial to growth and economic progress. Thus, economic nationalism can be defined as a mixture of trade protectionism and economic planning, with an aim to preserve national interests in the context of world markets.

Western countries managed to establish a global economy in which the transfer of goods, money, and technology needed to be regulated in an orderly way to ensure a continuous flow of natural resources and cheap labor for the industrialized world. Yet colonialism adversely affected the colonies. Under foreign rule, local economies could not find a chance to grow. Imported goods wiped out local ones. Colonialism also led to a cultural clash. The pressures to Westernize led the colonial people to reevaluate their traditions. But the good thing was Western countries introduced modern medicine that stressed the use of vaccines and more sanitary hygiene, helping to save lives and increase life expectancy. The correct answer is "E".

The correct answer is A.

For the Marxists, the determining element in international relations is economy (welfare) and other factors are neglected. 

Normative theories, essentially are related with the subjects of philosophy and ethic. Perpetual peace approach of Kant and European federation idea of J. J. Rousseau were interesting examples for normative studies.

The approach of social contract is another important approach which should be regarded for normative thought. According to Locke and Rousseau, by forming a higher authority, individuals would accept voluntarily to leave their certain rights to preserve their freedoms and security (freedom of life). Social contract theory depends on the assumption that the individuals might voluntarily bind themselves to the certain principles. In this sense, the correct answer is given in option B.

The correct answer is E.