The correct answer is option 2: 1995.

The General Agreement on Tariffs and Trade (GATT) was an international treaty established in 1947 with the goal of promoting free trade by reducing tariffs and other trade barriers among member countries.

In 1995, GATT was absorbed into the World Trade Organization (WTO) to expand on its functions and create a permanent international organization dedicated to overseeing global trade. The WTO was established as an international body to enforce trade rules, resolve disputes, and provide a forum for negotiations on trade-related matters.

Option 1 (1991) is incorrect because GATT was still operating independently at that time.

Option 3 (2000) is incorrect as well because the absorption of GATT into the WTO occurred before that year.

Option 4 (2005) is also incorrect because the absorption occurred earlier.

It is important to note that the establishment of the WTO built upon the foundation of GATT, incorporating its principles and agreements into the new organization.