The aims behind the setting up of the World Trade Organization (WTO) were primarily focused on promoting international trade and ensuring fair and transparent trading practices among nations. Let`s analyze each option provided:

I. Promotion of free trade and resource flows across countries.

This is one of the fundamental aims of the WTO. The organization works to reduce barriers to trade, such as tariffs, quotas, and discriminatory practices, to facilitate the free flow of goods and services across borders. The WTO promotes the principle of non-discrimination and encourages its member countries to treat all trading partners equally.

II. Protection of intellectual property rights.

Protection of intellectual property rights is indeed one of the aims of the WTO. The organization oversees the Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS), which sets minimum standards for intellectual property protection and enforcement. TRIPS ensures that member countries provide adequate legal protection for patents, trademarks, copyrights, and other forms of intellectual property.

III. Managing balanced trade between different countries.

While the WTO does not explicitly aim to manage balanced trade between countries, it does seek to ensure that trade is conducted on fair terms and that disputes between countries are resolved through a rules-based system. The WTO provides a platform for negotiations, discussions, and dispute settlement to address trade issues and prevent unfair trade practices.

IV. Promotion of trade between the former East Block countries and the western world.

The specific aim of promoting trade between the former East Block countries and the western world is not a stated objective of the WTO. However, the WTO does provide a framework for all member countries, including those from the former East Block, to engage in international trade and benefit from the global trading system.

Based on the analysis above, the correct answer would be Option 2: I and II. The WTO aims to promote free trade and resource flows across countries (Option I) and protect intellectual property rights (Option II). Although the other options contain partially accurate statements, they do not fully align with the primary aims of the WTO.