The capital city "Daidu," established by Kublai Khan, is situated at:

(B) Beijing

Daidu, also known as Khanbaliq, was the capital of the Yuan Dynasty under Kublai Khan. Today, it is known as Beijing, the capital of the People's Republic of China.

The World Trade Organization (WTO) officially came into existence on January 1, 1995. It replaced the General Agreement on Tariffs and Trade (GATT) and was established to facilitate international trade negotiations, resolve trade disputes, and provide a framework for the conduct of international trade. The WTO aims to promote free and fair trade among its member countries by establishing rules and agreements that govern global commerce. It serves as a forum for member nations to negotiate trade agreements and address issues related to trade policies and practices.